Great! All it needs now is updated CHANGES.md:

• a summary of the change
• a link to the newly created PR

If your change only affects a build plugin, and not the lib, then you only need to update the CHANGES.md for that plugin.

If your change affects lib in an end-user-visible way (fixing a bug, updating a version) then you need to update CHANGES.md for both the lib and the build plugins. Users of a build plugin shouldn't have to refer to lib to see changes that affect them.