Changes to link consistencies & Inspire program status

[asuiier]

Changes

• Updated legacy links from .com/groups/ to .com/communities/ for consistency with current Roblox site link formats.
• Updated Inspire creator program to be marked as closed due to applications not being open anymore.

Checks

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• To the best of my knowledge, all proposed changes are accurate.

[github-actions]

Hi @asuiier, thanks so much for helping improve the Roblox creator documentation! Our technical writing team will review your pull request soon. In the meantime, please ensure you've read through the README.md, contribution guidelines, and style recommendations.

[aetter]

Thanks a bunch @asuiier!