chore: add .gitblameignore file for ignore revisions from git blame

[jamiebuilds]

Summary

This is useful for ignoring commits like "Switch to hard tabs (#443)" which are almost never what you are looking for

Test Plan

#
# This file can be used to ignore certain revisions from git blame results
#
# To use it once:
#   $ git --ignore-revs-file .gitblameignore
#
# To use it all the time:
#   $ git config --local blame.ignoreRevsFile .gitblameignore
#
# If you add a commit to this file, please include the message of the commit and a link to its PR
#