Adds configurable-width gaps around the edge of your screen
https://extensions.gnome.org/extension/4827/edge-gap/
Heads up, maintenance on this is currently sparse at best. It's still doing what I want it to do on my Pop!_OS machine, and, while I'd like to add support for more features/gnome versions/etc., I only have so much time and energy. This project is currently a low priorty for me, unfortunately.
That said, if you'd like to contribute, I'd be happy to review your pull requests and will release new versions for any accepted changes!