docs: add typerror exception to active_branch method

docs: add typerror exception to active_branch method

fix: sphinx syntax

add author

Author: Patrick Gerard

AUTHORS

@@ -47,4 +47,5 @@ Contributors are:
 -Hugo van Kemenade
 -Hiroki Tokunaga <tokusan441 _at_ gmail.com>
 -Julien Mauroy <pro.julien.mauroy _at_ gmail.com>
+-Patrick Gerard
 Portions derived from other open source works and are clearly marked.

git/repo/base.py

@@ -858,6 +858,8 @@ def ignored(self, *paths: PathLike) -> List[str]:
     @property
     def active_branch(self) -> Head:
         """The name of the currently active branch.
+
+        :raises	TypeError: If HEAD is detached
         :return: Head to the active branch"""
         # reveal_type(self.head.reference)  # => Reference
         return self.head.reference