Fix docs for get_type_map (#1233)

src/pynwb/__init__.py

@@ -49,12 +49,12 @@ def _get_resources():
 @docval({'name': 'extensions', 'type': (str, TypeMap, list),
          'doc': 'a path to a namespace, a TypeMap, or a list consisting of paths to namespaces and TypeMaps',
          'default': None},
-        returns="the namespaces loaded from the given file", rtype=tuple,
+        returns="TypeMap loaded for the given extension or NWB core namespace", rtype=tuple,
         is_method=False)
 def get_type_map(**kwargs):
     '''
-    Get a BuildManager to use for I/O using the given extensions. If no extensions are provided,
-    return a BuildManager that uses the core namespace
+    Get the TypeMap for the given extensions. If no extensions are provided,
+    return the TypeMap for the core namespace
     '''
     extensions = getargs('extensions', kwargs)
     type_map = None