move styleguide to git

docs/index.md

@@ -35,7 +35,7 @@ Additional communication channels will be available starting from day 1 (27 Dece
 * [Tickets](https://tickets.events.ccc.de/RC3/)
 * [Merch](https://merch.rc3.world/) (order till 6th Dec, afterwards stuff may become unavailable!)
 * [HowTo rC3](https://howto.rc3.world/)
-* [Styleguide](https://styleguide.rc3.world/)
+* [Styleguide](https://git.cccv.de/rc3/rc3-style-guide)
 * [Angelsystem / Volunteers](https://engelsystem.de/rc3)
 * [Eventphone](https://guru3.eventphone.de/)
 * [CCC Event Blog](https://events.ccc.de/)