* 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
You can submit translations via [Crowdin](https://crowdin.com/project/mastodon). They are periodically merged into the codebase.
-[][crowdin]
+[](https://crowdin.com/project/mastodon)
## Pull requests