**Reason**:
DidYouMean has been proposed more than ten years ago (T10648) but never moved forward.
- [x] Archive documentation on `mediawiki.org` ( https://www.mediawiki.org/wiki/Extension:DidYouMean )
- [ ] Remove from `mediawiki/extensions` ( along with in `.gitmodules`)
- [x] Remove tests in `integration/config` ( `zuul/layout.yaml` )
- [ ] Remove from `translatewiki` ( `groups/MediaWiki/mediawiki-extensions.txt` / `groups/MediaWiki/mediawiki-skins.txt` )
- [x] Empty repository and add a OBSOLETE file.
- [x] Archive Phabricator project #MediaWiki-extensions-DidYouMean for associated extension
- [x] Edit Phabricator project #MediaWiki-extensions-DidYouMean description for associated extension with a link to this ticket
- [ ] Archive the extension's diffusion repository: ( https://phabricator.wikimedia.org/diffusion/EDYM/ )
- [ ] Mark the repository read-only in Gerrit: ( https://gerrit.wikimedia.org/r/#/admin/projects/mediawiki/extensions/DidYouMean )
- [ ] Delete the GitHub mirror: https://github.com/wikimedia/mediawiki-extensions-DidYouMean