Add instructions to up-merge branches after merging release clone.

pep-0101.txt

@@ -572,6 +572,18 @@ How to Make A Release
       (usually only one, except if you made a new maintenance release).
       Easily resolvable conflicts may appear in Misc/NEWS.
 
+      If releasing from other than the default branch, remember to carefully
+      merge any touched branches with higher level branches, up to default.  For
+      example:
+
+      $ hg update -C default
+      $ hg resolve --list
+      $ hg merge --tool "internal:fail" 3.4
+
+      ... here, revert changes that are not relevant for the default branch...
+
+      $ hg resolve --mark
+
       Commit and push to the main repo.
 
   ___ You can delete the remote release clone, or simply reuse it for the next