Release 2.2.1

[bryce13950]

• Updated README to have Bryce as the maintainer

• Fix attention result projection

Current result projection for attention is incorrect. Type annotations would suggest that result isn't being summed over head_index, but in fact it is. I've edited the function so that it's no longer being summed over head_index.

Note, this bug caused the ARENA material to fail for the first transformers chapter, I've tested it and it now works.

• fix formatting with black

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Description

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Fixes # (issue)

Type of change

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• [ ] 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 not work as expected)
• [ ] This change requires a documentation update

Screenshots

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Checklist:

• [ ] I have commented my code, particularly in hard-to-understand areas
• [ ] I have made corresponding changes to the documentation
• [ ] My changes generate no new warnings
• [ ] I have added tests that prove my fix is effective or that my feature works
• [ ] New and existing unit tests pass locally with my changes
• [ ] I have not rewritten tests relating to key interfaces which would affect backward compatibility