I would like to implement a Changelog in the form of a frame, which is displayed on top of the Polarion-Website (similar to what Wikipedia does with this donation-seeking frame

). The frame should show up to all users as soon as an Admin edited the changelog. Additionally the frame should include a Button for closing the frame (and keeping it closed for this user until the next update of changelog by any Admin).
Little Mockup:

I am grateful for any kind of help!