Renamed Veschwendungsfasten to foodsharing-Städte

What does this MR do?

Renames "Verschwenungsfasten" to "foodsharing-Städte"

How confident are you it won't break things if deployed?

very confident, nothing major changed

Checklist

• added a test, or explain why one is not needed/possible...
• no unrelated changes
• asked someone for a code review
• joined #foodsharing-beta channel at https://slackin.yunity.org
• added an entry to CHANGELOG.md (description, merge request link, username(s))
• Once your MR has been merged, you are responsible to update the #foodsharing-beta Slack channel about what has been changed here. They will test your work in different browsers, roles or other settings