A hardware-accelerated GPU terminal emulator focusing to run in desktops and browsers.

Update nix files (#1319) master

* Format with `alejandra` and add it to all devShells * Use `lib.fileset` to get only the needed files for the build * Fix build inputs for Darwin * Make `wayland` and `x11` optional using the package args `with*` * Create a separate `terminfo` output[^1] * Fix nix file indentation to 2 instead of 4 * Remove `app`, `package` already has a `meta.mainProgram` attribute * Add an overlay that can be used to override the `rio` package using flake-part's easyOverlay module[^2] * Create separate package for `msrv`, `stable` and `nightly`, matching the different `devShells` available * Removed the `flake = false` attribute for `inputs.systems` * Create `legacyPackages.rio` containing four sub packages using different versions of the rust-toolchain: * `rio.msrv` - uses `./rust-toolchain.toml` * `rio.stable` - uses `rust-bin.stable` * `rio.nightly` - uses the latest nightly rust * `rio.default` - Same as `rio.msrv` * Added `/result` to get rid of the `nix build` output file[^3] [^1]: https://github.com/NixOS/nixpkgs/blob/nixos-unstable/pkgs/by-name/ri/rio/package.nix [^2]: https://flake.parts/options/flake-parts-easyoverlay [^3]: A simpler version of #1233, that _just_ adds this one line