Add to Git commit logs discussion in README.md
Add to Git commit logs discussion in README.md

Includes:

* Providing more structure to README.md (i.e. adding 'Git Commit Messages'
  section) to enable more types of conventions for Git around tagging, etc.
* Add discussion and examples around good and bad examples of Git commit
  messages.
* Add section on linking issues in the Git commit messages/logs.

mbbx6spp/styleguides,lookout/styleguides,polynomial/styleguides