bpo-30406: Make async and await proper keywords (#1669)

Per PEP 492, 'async' and 'await' should become proper keywords in 3.7.
diff --git a/Lib/pydoc.py b/Lib/pydoc.py
index 8dc3c0a..01f7a32 100644
--- a/Lib/pydoc.py
+++ b/Lib/pydoc.py
@@ -1703,7 +1703,7 @@
     # in pydoc_data/topics.py.
     #
     # CAUTION: if you change one of these dictionaries, be sure to adapt the
-    #          list of needed labels in Doc/tools/pyspecific.py and
+    #          list of needed labels in Doc/tools/extensions/pyspecific.py and
     #          regenerate the pydoc_data/topics.py file by running
     #              make pydoc-topics
     #          in Doc/ and copying the output file into the Lib/ directory.
@@ -1715,6 +1715,8 @@
         'and': 'BOOLEAN',
         'as': 'with',
         'assert': ('assert', ''),
+        'async': ('async', ''),
+        'await': ('await', ''),
         'break': ('break', 'while for'),
         'class': ('class', 'CLASSES SPECIALMETHODS'),
         'continue': ('continue', 'while for'),