[Docs] Fix vmmap docstring. (#1981)

* Fix vmmap docstring.

* Update vmmap.py

---------

Co-authored-by: Disconnect3d <dominik.b.czarnota@gmail.com>

pwndbg/gdblib/vmmap.py

@@ -348,6 +348,7 @@ def coredump_maps():
 def info_proc_maps():
     """
     Parse the result of info proc mappings.
+
     Returns:
         A tuple of pwndbg.lib.memory.Page objects or None if
         info proc mapping is not supported on the target.