consolidated script documentation into a single md file

wrote documentation on terminal sound effects

added a sound effect for `invoke`

added the function `build-drv`, which is a wrapper for nix-build that
puts the output nix store path to the derivation into an environment
variable instead of symlinking it in the current working directory

modules/home/environment/userpkgs.nix

@@ -44,6 +44,7 @@ in {
   config = lib.mkIf config.movOpts.envConfig.userPkgs.enable {
     home.packages = with pkgs; [
       nemo
+      feh
       yubikey-manager
       yubikey-personalization
       gtk3