devel-docs: add a point about publishing to the Microsoft Store.

See issue #1307.
There doesn't seem to be anything blocking us to publish to the
Microsoft Store, now that there is this new "traditional desktop
application" process allowing us to publish using our existing
installer. So GIMP 2.10.32 should normally be our first published
version there.

devel-docs/release-howto.txt

@@ -36,9 +36,9 @@
 
  ( ) Notify the maintainers of the official builds for Windows
      (irc:ender/@jernejs), macOS (irc:Samm/@samm-git and
-     irc:DesMcG/@DesMcGuinness) and flatpak (irc:Jehan/@Jehan) of the
-     upcoming release so they have some time to sort out issues with
-     their builds.
+     irc:DesMcG/@DesMcGuinness) and flatpak (irc:Jehan/@Jehan,
+     @harrymichal and @hfiguiere) of the upcoming release so they have
+     some time to sort out issues with their builds.
 
  ( ) Wait until the date specified in the announcements, use this time
      to get bug fixes applied which don't modify strings.
@@ -244,9 +244,18 @@
          we publish with most mirrors lagging behind, many download
          errors will occur.
 
- ( ) When confident about the installers availability, announce the
-     release on gimp.org and send a release announcement to the
-     gimp-user and gimp-developer mailing lists.
+ ( ) When confident about the installers availability, if this is a
+     stable release, create a new package on the Microsoft Partner
+     Center so that GIMP becomes available on the Microsoft Store:
+     https://partner.microsoft.com/en-us/dashboard/apps-and-games/overview
+
+     The URL to provide is the mirror URL, not the direct URL.
+
+     Current people with admin access to this platform:
+     irc:ender/@jernejs and irc:Jehan/@Jehan.
+
+ ( ) Announce the release on gimp.org and send a release announcement to
+     the gimp-user and gimp-developer mailing lists.
 
      [ ] Check out the gimp-web master branch and merge or cherry-pick
          the changes you did in the testing branch.