There's a third-party theme called PhotoGIMP which changes the layout and shortcuts to match Photoshop: https://github.com/Diolinux/PhotoGIMP

Longterm, we have a roadmap item for an Extensions platform: https://developer.gimp.org/core/roadmap/#extensions

So basically, you could download plug-ins, themes, shortcut presets, etc, directly into GIMP. We have a lot of pieces done - we just need someone to focus on it to finish.