Add .git-blame-ignore-revs

[hyperupcall]

Description

Adds the file.

Motivation and Context

Was looking through the blame of some files, and some shfmt-related commits got in the way, so I created a .git-blame-ignore-revs file to filter those out. Unfortunately, shfmt was not applied all in one commit, and many of the shfmt-related commits also mix in ShellCheck and other miscellaneous changes. So there aren't many commits that can actually be placed in this file - I listed a few of the most relevant ones, hopefully it should be enough in the most relevant places.

How Has This Been Tested?

As per linked docs page this can be used through the --ignore-revs-file flag. In VSCode this is used automatically.

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• If my change requires a change to the documentation, I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• If I have added a new file, I also added it to clean_files.txt and formatted it using lint_clean_files.sh.
• I have added tests to cover my changes, and all the new and existing tests pass.

[seefood]

interesting approach, First time I see this git trick. I like it :) I wish I knew about it before...