The Heroic Games Launcher has built-in support for running games with GameMode.
This change makes the client executable available in the Heroic FHS environment,
but the NixOS module will need to be enabled on the host system.
* Instead of using the prebuilt AppImage, build from source and wrap with
Electron from nixpkgs.
* Wrap in FHS user environment with buildFHSUserEnvBubblewrap.
* Correct meta.description to mention GOG support.
* Simplify meta attribute
* Update maintainers.
Taking over sole maintainership from wolfanguakang.
* Use gogdl and legendary-gl from nixpkgs
