Small grammar fixes and rewording (#132)

* Small grammar fixes and rewording

Reword some sentences to read more naturally and also adjust the
grammar a bit here and there.

Author: CounterPillow

content/config/create_as.md

@@ -10,12 +10,12 @@ nav_order: 10
 
 In order to create a SCIONLab AS you must login on [SCIONLab](https://www.scionlab.org). In case you don't have an account yet, please follow the registration process.
 
-After loggin in, you land on the `My ASes` page.
+After logging in, you will land on the `My ASes` page.
 
 ![Empty SCIONLab MyASes page](../images/scionlab_user_page_empty.png)
 
 * The `My ASes` link in the navbar brings you back to this page when you navigate away.
-* The drop-down menu under the <span class="fa fa-user"></span>-symbol in the navbar contains links to change your password and log-out.
+* The drop-down menu under the <span class="fa fa-user"></span>-symbol in the navbar contains links to change your password and to log out.
 
 This view is initially empty, later you will see a list of your ASes:
 
@@ -24,12 +24,12 @@ This view is initially empty, later you will see a list of your ASes:
 * The columns in this summary refer to the configuration you've made for this AS, as discussed below.
 * The link with the <span class="fa fa-pencil"></span>-symbol in the `AS ID` column  brings you to the edit page for an AS.
 * The link with the <span class="fa fa-download"></span>-symbol in the `Configuration` column lets you download the configuration tarfile for an AS.
-* The tick or cross in the `Active` column indicate whether an AS has been deactivated (using the corresponding button in the edit page).
+* The tick or cross in the `Active` column indicates whether an AS has been deactivated (using the corresponding button on the edit page).
 
 
 ## Configure a SCIONLab AS
 
-The `Create a new SCIONLab AS` button or on the edit link for an existing AS will bring you to the same configuration form.
+The `Create a new SCIONLab AS` button or the edit link for an existing AS will bring you to the same configuration form.
 
 ![Configure ASes form](../images/scionlab_user_as_form.png)
 
@@ -57,7 +57,7 @@ The following options are the parameters for the overlay link between the border
     * you are **behind a NAT or firewall** and you cannot open/forward a chosen UDP port
     * you want to _"just make it work"_, as you'll need to know no further details about your network configuration
 
-    The configuration file will contain an OpenVPN configuration file `client.conf`.
+    The configuration file will contain an OpenVPN configuration file named `client.conf`.
     After extracting this file to `/etc/openvpn/`, you can start the tunnel by running `sudo systemctl start openvpn@client`.
 
 *   Public IP Address, Bind IP Address
@@ -73,11 +73,10 @@ The following options are the parameters for the overlay link between the border
 
 
 
-    If your host has a public IP (the public IP is identical with the local IP), only fill the `Public IP Address` field and
-    leave the `Bind IP Address` field blank.
+    If your host has a public IP (the public IP is identical with the local IP), only fill in the `Public IP Address` field and leave the `Bind IP Address` field blank.
 
 
-    If you are in a network behind a NAT (the public IP and local IP are different), fill the `Public IP Address` field with the public IP and the `Bind IP Address` field with the local IP address.
+    If you are in a network behind a NAT (i.e. the public IP and local IP are different), fill the `Public IP Address` field with the public IP and the `Bind IP Address` field with the local IP address.
 
 
 {% include alert type="note" content="

content/faq/join_infrastructure.md

@@ -29,7 +29,7 @@ There are a few requirements for you or your organization to join SCIONLab as an
 
 - Infrastructure ASes and nodes are required to be active 24 hours a day, 7 days a week. The SCIONLab administrators can typically handle all SCION related problems, but sometimes they will contact you if they cannot perform certain tasks. An example would be to change a drive if it failed, etc.
 - The machine should have a minimum of 4 CPUs, 8 GB of RAM and 40 GB of disk space. In most of the cases a VM can suffice.
-- OS for the SCION infrastructure node must be Ubuntu 18.04.
+- The OS for the SCION infrastructure node must be Ubuntu 18.04.
 - The border router node(s) must have a public static IP address. Any other SCION services can run with private static IP addresses.
 - Any firewalls affecting the node must be configured according to the [SCION AS connectivity matrix](./as_connectivity.html).
 
@@ -39,4 +39,4 @@ The following are not requirements, but recommendations:
 
 - The border router should be near (latency-wise) the IP border of your AS or organization.
 - Co-locating the nodes in your datacenter is usually a good idea as it reduces network latency.
-- Given the fact SCIONLab is a research network dedicated mainly for running experiments, you may want to place the SCIONLab node(s) in a DMZ or a dedicated subnet.
+- Given the fact that SCIONLab is a research network dedicated mainly to running experiments, you may want to place the SCIONLab node(s) in a DMZ or a dedicated subnet.

content/faq/troubleshooting.md

@@ -59,12 +59,12 @@ The following relate to AS [configured to use VPN](../config/create_as.html#conf
 
 Check the OpenVPN client log for specific information, using `sudo journalctl -e -u openvpn`.
 
-An unspecific timeout typically indicates that your behind a firewall that blocks UDP port 1194. Please contact your network administrators to unblock this port.
+An unspecific timeout typically indicates that you are behind a firewall that blocks UDP port 1194. Please contact your network administrators to unblock this port.
 
 
 #### Border Router fails to start
 
-If you see (e.g. that your border router did not start, it is likely that the border router was trying to start before the VPN tunnel interface was up.
+If you see for example that your border router did not start, it is likely that the border router was trying to start before the VPN tunnel interface was up.
 
 Simply try again;
 
@@ -86,7 +86,7 @@ The following are common issues or troubleshooting strategies for a SCION AS.
 
 Typically, this indicates a configuration error.
 
-If you've configured to use VPN, check the "Border Router fails to start" entry in the VPN section above.
+If you've configured to use a VPN, check the "Border Router fails to start" entry in the VPN section above.
 
 Inspect the logs of the failed services to find details.
 In case of multiple failures, fixing issues in the following order usually works best:
@@ -105,7 +105,7 @@ First clear the `/var/log/scion/` directory and restart. This often helps to fin
 
 Log of the beacon server (`/var/logs/scion/bs*.log`) does not contain recent entries referring to `Registered beacons`.
 
-As at the time of writing there are certain failure modes of the border routers that are hard to diagnose and are fixed with a simple restart, first thing to try is to turn it off and on again:
+As at the time of writing there are certain failure modes of the border routers that are hard to diagnose and are fixed with a simple restart, the first thing to try is to turn it off and on again:
 
 ```
 sudo systemctl restart scionlab.target

content/install/src.md

@@ -6,8 +6,8 @@ nav_order: 30
 
 # Building from sources (Linux)
 
-If you're planning to make modifications to SCION implementation, you can build SCION from sources and run your SCIONLab AS with your own version of SCION.
-For developer's convenience, SCIONLab supports generating configurations that are compatible with the scripts and machinery intended to run SCION in a development environment.
+If you are planning to make modifications to the SCION implementation, you can build SCION from sources and run your SCIONLab AS with your own version of SCION.
+For developers' convenience, SCIONLab supports generating configurations that are compatible with the scripts and machinery intended to run SCION in a development environment.
 
 Building SCION from sources requires following a lengthy setup procedure and installing various development dependencies.
 The development setup is currently supported/documented for **Ubuntu 16.04 _only_**.
@@ -33,7 +33,7 @@ on top of SCION.
 After having managed to build SCION and after [creating or modifying your AS](../config/create_as.html) in the SCIONLab coordination website, you can deploy the generated configuration to your machine.
 
 1. Download the configuration tarfile from the SCIONLab coordination website.
-2. If using VPN, unpack the `client.conf` to `/etc/openvpn/` and start OpenVPN
+2. If you plan on using a VPN, unpack the `client.conf` to `/etc/openvpn/` and start OpenVPN
    ```shell
    sudo systemctl restart openvpn@client
    ```

content/install/vm.md

@@ -6,7 +6,8 @@ nav_order: 10
 
 # Running inside a VM
 
-## Install Vagrant and Virtualbox
+## Installing Vagrant and VirtualBox
+
 If you choose to run a SCIONLab virtual machine, you need to install [Vagrant](https://www.vagrantup.com/) and
 [VirtualBox](https://www.virtualbox.org/). These are available for most platforms, including Linux, Windows and macOS.
 
@@ -24,7 +25,7 @@ For other platforms, please consult the official installation instructions:
 ## Using Vagrant to run the VM
 
 After [creating your AS](../config/create_as.html) in the SCIONLab coordination
-website, you will be able to download a tarfile with `Vagrantfile` allowing you to easily build your SCIONLab VM.
+website, you will be able to download a tarfile containing a `Vagrantfile` which allows you to easily build your SCIONLab VM.
 
 {% include alert type="note" content="
 All the commands below need to be executed from the directory containing the Vagrantfile.
@@ -36,8 +37,9 @@ To start your VM, run
 vagrant up
 ```
 
-When running your VM for the first time, base Ubuntu OS will be installed together with SCIONLab packages and their
-dependencies. After the installation SCIONLab services should be already up and running.
+When running your VM for the first time, the base Ubuntu OS will be installed together with the
+SCIONLab packages and their dependencies. After the installation, SCIONLab services should already
+be up and running.
 
 Once the `vagrant up` command returns the prompt, you can connect to your VM to
 start exploring:
@@ -46,10 +48,10 @@ start exploring:
 vagrant ssh
 ```
 
-The directory containing the Vagrant file is synced with the VM where the files
+The directory containing the Vagrant file is synced with the VM, in which the files
 will appear in the `/vagrant/` directory.
 This is a convenient way to share files between your host machine and your
-VM, and allows to move data both ways.
+VM, and enables moving data both ways.
 
 {% include alert type="note" content="
 You can use following Vagrant commands to perform various operations with your VM