[repo] Add Git commit message template
[repo] Add Git commit message template

Commit messages can be messy, unorganized, and hard to read at a quick glance.
This change introduces a message template based on
[http://blog.ssanj.net/posts/2015-10-22-git-commit-message-format.html]

JoeLoser/Metafunctions_and_Traits_Toolkit,JoeLoser/Metafunctions_and_Traits_Toolkit,JoeLoser/Metafunctions_and_Traits_Toolkit