add missing autocompletions (#514)

* added missing autocompletions:
- code-block
- container
- header
- image
- link
- pdf

* added extraTags ([name=], [time=], [color=]) to the link autocompletion, because they trigger on the same characters
added getUser in /redux/user/methods to retrive the current user outside of .tsx files
improve the regexps on several autocompletion

* renamed hints to auto
Co-authored-by: Erik Michelson <github@erik.michelson.eu>
Co-authored-by: Tilman Vatteroth <tilman.vatteroth@tu-dortmund.de>

src/redux/user/methods.ts

@@ -15,3 +15,7 @@ export const clearUser: () => void = () => {
   }
   store.dispatch(action)
 }
+
+export const getUser = (): UserState | null => {
+  return store.getState().user
+}