Add helper script snippet for following renames

[mschoettle]

The current example does not follow renames which I think should be included to know the very first time the file was introduced.
For some reason, git log --reverse --follow does not work properly. So reversed it to use tail instead of head.

I added an extra section but it might be worth to add it to the existing examples instead.

• Added self to AUTHORS.rst.

• My changes do not contradict
  the current specification.
• I agree to license my contribution under the licenses indicated in the
  changed files.

• Added a change log entry in changelog.d/<directory>/.

I feel that the changes are too small and do not affect the tool itself, so I did not add one. If you disagree, I'll be happy to add a changelog entry.

• Added self to copyright blurb of touched files.

Is this necessary in this case?