I had misunderstood what a .app package was, thanks for clarifying. So do people package things like linters and language servers into the .app also? Like, is

I had misunderstood what a .app package was, thanks for clarifying. So do people package things like linters and language servers into the .app also? Like, is it everything I'd need to work on the app, or is just everything I'd need to run the app?