fix: better clarity on username/gitAuthor and modified branches

[rarkins]

Changes

Improve docs on username/gitAuthor plus improve log message when branch is considered modified.

Context

Documentation (please check one with an [x])

• [x] I have updated the documentation, or
• [ ] No documentation update is required

How I've tested my work (please select one)

I have verified these changes via:

• [x] Code inspection only, or
• [ ] Newly added/modified unit tests, or
• [ ] No unit tests but ran on a real repository, or
• [ ] Both unit tests + ran on a real repository