Add host modules and home options; update README

modules/core/steam.nix

@@ -1,20 +1,43 @@
-{pkgs, ...}: {
-  programs = {
-    steam = {
+{
+  pkgs,
+  lib,
+  config,
+  ...
+}: {
+  options = {
+    steam.enable = lib.mkEnableOption "Steam";
+    gamescope.enable = lib.mkEnableOption "Gamescope";
+    gamemode.enable = lib.mkEnableOption "Gamemode";
+  };
+
+  config.programs = {
+    steam = lib.mkIf config.steam.enable {
       enable = true;
+      package = pkgs.steam;
       remotePlay.openFirewall = true;
       dedicatedServer.openFirewall = true;
-      gamescopeSession.enable = true;
+      gamescopeSession = lib.mkIf config.gamescope.enable {
+        enable = true;
+        args = [
+          "--rt"
+          "--expose-wayland"
+        ];
+      };
       extraCompatPackages = [pkgs.proton-ge-bin];
     };
-    # gamescope = {
-    #   enable = true;
-    #   capSysNice = true;
-    #   args = [
-    #     "--rt"
-    #     "--expose-wayland"
-    #   ];
-    # };
-    gamemode.enable = true;
+
+    gamescope = lib.mkIf config.gamescope.enable {
+      enable = true;
+      capSysNice = true;
+      args = [
+        "--rt"
+        "--expose-wayland"
+      ];
+    };
+
+    gamemode = lib.mkIf config.gamemode.enable {
+      enable = true;
+      enableRenice = true;
+    };
   };
 }