fix: sphinx "Unexpected indentation" warning

Problem:

    sphinx: pynvim.api.nvim.Nvim.feedkeys:7: ERROR: Unexpected indentation.

Solution:
Delete most of the docstring. We should not have redundant docs in the
clients...

pynvim/api/nvim.py

@@ -375,14 +375,7 @@ def chdir(self, dir_path: str) -> None:
         return self.request('nvim_set_current_dir', dir_path)
 
     def feedkeys(self, keys: str, options: str = '', escape_csi: bool = True) -> None:
-        """Push `keys` to Nvim user input buffer.
-
-        Options can be a string with the following character flags:
-        - 'm': Remap keys. This is default.
-        - 'n': Do not remap keys.
-        - 't': Handle keys as if typed; otherwise they are handled as if coming
-               from a mapping. This matters for undo, opening folds, etc.
-        """
+        """Push `keys` to Nvim user input buffer."""
         return self.request('nvim_feedkeys', keys, options, escape_csi)
 
     def input(self, bytes: AnyStr) -> int: