chore: fix link

README.md

@@ -8,5 +8,5 @@ Documentation for this is done with GitLab Pages using MkDocs and is available h
 If you don't want to open the Webpage or it is not available for whatever reason,
 the documentation root is found [here][docs-root]
 
-[docs-root]: /dtt/documentation/docs/index.md
+[docs-root]: https://transfer.hft-stuttgart.de/gitlab/dtt/documentation/-/blob/master/docs/index.md
 [pages-link]: https://transfer.hft-stuttgart.de/pages/dtt/