format style guide more nicely

Author: wyattscarpenter

mypy/main.py

@@ -535,17 +535,16 @@ def add_invertible_flag(
     # their `dest` prefixed with `special-opts:`, which will cause them to be
     # parsed into the separate special_opts namespace object.
 
-    # Note: we have a style guide for formatting the mypy --help text:
-    # # Command line flag conventions
-    # This section documents our style guide for formatting the output of running `mypy --help`.
-    # ## Flags
+    # Our style guide for formatting the output of running `mypy --help`:
+    # Flags:
     # 1.  The flag help text should start with a capital letter but never end with a period.
     # 2.  Keep the flag help text brief -- ideally just a single sentence.
     # 3.  All flags must be a part of a group, unless the flag is deprecated or suppressed.
     # 4.  Avoid adding new flags to the "miscellaneous" groups -- instead add them to an
     #     existing group or, if applicable, create a new group. Feel free to move existing
     #     flags to a new group: just be sure to also update the documentation to match.
-    # ## Groups
+    #
+    # Groups:
     # 1.  The group title and description should start with a capital letter.
     # 2.  The first sentence of a group description should be written in the imperative mood.
     #     Tip: try substituting the group title and description into the following sentence: