Update installation instructions in docs

Author: urfeex

ur_simulation_gz/doc/installation.rst

@@ -3,10 +3,44 @@
 Installation
 ============
 
-Skip any of below steps is not applicable.
+You can install the Universal Robots ROS2 GZ Simulation package in two ways:
+
+1. **From binary packages**: This is the recommended way for most users, as it is quick and easy.
+2. **From source**: This is useful if you want to modify the code or if you require to have a
+   version that is newer than the latest binary package available.
+
+Installation from binary packages
+---------------------------------
+
+1. `Install ROS2 <https://docs.ros.org/en/rolling/Installation/Ubuntu-Install-Debians.html>`_
+2. Install the package using
+
+.. code-block:: bash
+
+  sudo apt-get install ros-${ROS_DISTRO}-ur-simulation-gz
+
+That's it! You can now use the Universal Robots ROS2 GZ Simulation package in your ROS 2
+environment. See the :ref:`ur_simulation_gz_usage` section for how to use it.
+
+
+Installation from source
+------------------------
+
+.. note::
+   This section is only required if you want to build the package from source. Please do that
+   only, if that's required for you. Reasons why you would need to build it from source are:
+
+   - You built one of multiple of this package's dependencies from source and want to use it with
+     this package.
+   - You want to develop this package or contribute to it. If you only want to modify the launch
+     files to fit your application, a better approeach would be to create your own package with
+     your own launch files that include the ones from this package.
+
+   To rather install the binary packages, please refer to the `Installation from binary
+   packages`_ section above.
 
 Setup ROS2 Workspace
---------------------
+~~~~~~~~~~~~~~~~~~~~
 
 1. Create a colcon workspace:
 
@@ -30,11 +64,10 @@ Setup ROS2 Workspace
 
     $ cd $COLCON_WS
     $ git clone -b ros2 https://github.com/UniversalRobots/Universal_Robots_ROS2_GZ_Simulation.git src/ur_simulation_gz
-    $ vcs import --input src/ur_simulation_gz/ur_simulation_gz-not-released.rolling.repos src # only required for rolling
     $ rosdep update && rosdep install --ignore-src --from-paths src -y
 
 Configure and build Workspace
------------------------------
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 To configure and build the workspace execute following commands:
 

ur_simulation_gz/doc/usage.rst

@@ -1,5 +1,7 @@
 :github_url: https://github.com/UniversalRobots/Universal_Robots_ROS2_GZ_Simulation/blob/ros2/ur_simulation_gz/doc/usage.rst
 
+.. _ur_simulation_gz_usage:
+
 Usage
 =====