feat: see methods from the bound function

Signed-off-by: nstarman <[email protected]>

Author: nstarman

plum/function.py

@@ -515,3 +515,8 @@ def wrapped_method(*args, **kw_args):
         # extended, so unwrapping is likely never desired.
 
         return wrapped_method
+
+    @property
+    def methods(self) -> List[Signature]:
+        """list[:class:`.signature.Signature`]: All available methods."""
+        return self._f.methods