close #19

- Updated GNU social's ActivityPub plugin's repository address
- s/GNU Social/GNU social

The actual codes of the project seems like untouched for a long time.

Fix typo 'disbin' -> 'distbin' in README

Thanks for listing distbin! There is a 't' missing and this adds it.

Fix typo in README

close #10

https://github.com/sindresorhus/awesome/pull/1389#issuecomment-467380767

Update README.md

- Missing License section
- Incorrect indentation before bullet: remove 1 space
- ToC item "Platforms" does not match corresponding heading "Services"
- Missing newline character at end of file
- List item description must end with proper punctuation
- Dead links (in this case, Kroeg only)

Taken from sindresorhus/awesome.

Services, Implementations, Libraries, Bridges are sorted.

I'm not 100% sure if they are abandoned or not.
So please let me know if some of removed projects are active.

Special thanks to: @wakest@mastodon.social

Special thanks to: @wakest@mastodon.social

- Rustodon in Platforms
- ActivityPub Example in Implementations