zealdocs/zeal ? reverse-engineered prompt

Build me a desktop app for browsing offline developer documentation, kind of like a personal reference library that searches instantly even when there’s no internet. I want to be able to install different doc sets from inside the app, keep them all in one place, and search across them quickly, with the option to narrow results to one doc set or a few specific ones. It should feel polished and simple to use on Linux and Windows, and it would be nice if I can open it from the command line with a search term too. Make the interface clean, fast, and focused on helping me find API docs and reference material without any fuss. If you need to, look up the current docs for any libraries or build setup details online.