Make sure blog post MR has WIP keyword

doc/release/monthly.md

@@ -156,6 +156,7 @@ Tweet about the RC release:
 1. Also check the CI changelog
 1. Add a proposed tweet text to the blog post WIP MR description.
 1. Create a WIP MR for the blog post
+1. Make sure merge request title starts with `WIP` so it can not be accidently merged until ready.
 1. Ask Dmitriy (or a team member with OS X) to add screenshots to the WIP MR.
 1. Decide with core team who will be the MVP user.
 1. Create WIP MR for adding MVP to MVP page on website