Show inheritance in exceptions docs.

Julian · Julian · commit ebc8d3c592ca · 2023-02-08T14:24:50.000+01:00
(The only place it's allowed/used essentially).

But this is needed to tell users that for ref exception
catching, in theory they may want to catch only Unresolvable
and thereby all subclasses.
diff --git a/docs/api.rst b/docs/api.rst
@@ -34,6 +34,7 @@ referencing.exceptions
 
 .. automodule:: referencing.exceptions
    :members:
+   :show-inheritance:
    :undoc-members:
 
 
