Co-authored-by: Jake Paustian <jake1500@iastate.edu>

See #20284

* Change references to tootsuite/mastodon to mastodon/mastodon

* Remove obsolete test fixture

* Replace occurrences of tootsuite/mastodon with mastodon/mastodon in CHANGELOG

And a few other places

Edited to improve clarity, concision, and assertiveness

* Fix crowdin badge display in CONTRIBUTING.md

The Crowdin localization badge in `CONTRIBUTING.md` appeared to have the wrong markup around it. This manifested in some extra brackets and an unformatted `crowdin` string.

* Make Crowdin badge a link to the Mastodon project

Restore and change from 89096860

The mastodon project no longer used weblate to translate UI
sentences. (ref #10385)

* Update CONTRIBUTING.md

* Update CONTRIBUTING.md

* Update CONTRIBUTING.md

* Update CONTRIBUTING.md

* Remove docker guide and put it in docs repo

* Move tasks to docs repo

* Move requirements to contributing doc

* Move advice about tagged releases to docs repo

* Move local domain and host config to docs repo

* Link to related tech

* Rubocop link for Sublime Text

* Fix rubocop links

* Link to gh issues page from contributing doc

This addition to the submission guidelines requests that contributors remember to document their code. It's not a hard fast rule just a reminder.