Merge pull request #293 from src-d/vmarkovtsev-patch-7

Backport from Hacktoberfest edits

Author: mcuadros

engineering/documents/CONTRIBUTING.md

@@ -7,12 +7,12 @@ and other resources to make it easier to get your contribution accepted.
 
 ## Certificate of Origin
 
-By contributing to this project you agree to the [Developer Certificate of
+By contributing to this project, you agree to the [Developer Certificate of
 Origin (DCO)](DCO). This document was created by the Linux Kernel community and is a
 simple statement that you, as a contributor, have the legal right to make the
 contribution.
 
-In order to show your agreement with the DCO you should include at the end of commit message,
+In order to show your agreement with the DCO you should include at the end of the commit message,
 the following line: `Signed-off-by: John Doe <[email protected]>`, using your real name.
 
 This can be done easily using the [`-s`](https://github.com/git/git/blob/b2c150d3aa82f6583b9aadfecc5f8fa1c74aca09/Documentation/git-commit.txt#L154-L161) flag on the `git commit`.
@@ -34,7 +34,7 @@ issue you're facing, or it's a known issue that we're already aware of.
 ## How to Contribute
 
 Pull Requests (PRs) are the main and exclusive way to contribute code to source{d} projects.
-In order for a PR to be accepted it needs to pass a list of requirements:
+In order for a PR to be accepted it needs to pass this list of requirements:
 
 - The contribution must be correctly explained with natural language and providing a minimum working example that reproduces it.
 - All PRs must be written idiomaticly: