Update cont aa1 to master (Update CONTRIBUTING.md)

[pinterid]

Checklist:

• Have you added an explanation of what your changes do and why you'd like them to be included?
• Have you updated or added documentation for the change?
• Have you tested your changes with successful results?

Type of Changes:

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

What is the current behavior? (link to any open issues here)

• Currently the contributing guidelines are outdated. Update Contributing Guidelines #3

What is the new behavior (if this is a feature change)?

• Now the contributing guidelines are up to date. Closes Update Contributing Guidelines #3

Other information:

• Ref: 🐍

[Aichnerc]

LGTM

[kleberbaum]

Should be ok to merge.

[schettn]

lgtm