Merge branch 'commit-message-contribution' into 'master'

Articles on proper commit messages

2 Articles on commit messages

[ci skip]

See merge request !3831

CONTRIBUTING.md

@@ -323,6 +323,7 @@ request is as follows:
    [shell command guidelines](doc/development/shell_commands.md)
 1. If your code creates new files on disk please read the
    [shared files guidelines](doc/development/shared_files.md).
+1. When writing commit messages please follow [these](http://tbaggery.com/2008/04/19/a-note-about-git-commit-messages.html) [guidelines](http://chris.beams.io/posts/git-commit/).
 
 The **official merge window** is in the beginning of the month from the 1st to
 the 7th day of the month. This is the best time to submit an MR and get