* handle trailing comma in import list properly
* no longer backup .ghcup in gitpod
* fix for ghc < 9
* fix it without using CPP
* explain gitpod change
* read trailing comma before adding one
* refine imports
* refine gitpod
* gitpod store ghcide and hie-bios cache
These cache directories are small, but not preserving them requires
HLS to compile all modules in local project on workspace restarts.
* fix code styling
