added opengl and nvidia configs

nixos/opengl.nix

@@ -0,0 +1,32 @@
+{ pkgs, ... }:
+
+{
+
+  nixpkgs.config.packageOverrides = pkgs: {
+    intel-vaapi-driver = pkgs.intel-vaapi-driver.override { enableHybridCodec = true; };
+  };
+
+  # Enable OpenGL
+  hardware.opengl = {
+    enable = true;
+    driSupport = true;
+    driSupport32Bit = true;
+    extraPackages = with pkgs; [
+      intel-compute-runtime
+      intel-media-driver    # LIBVA_DRIVER_NAME=iHD
+      intel-vaapi-driver    # LIBVA_DRIVER_NAME=i965 (older but works better for Firefox/Chromium)
+      vaapiVdpau
+      libvdpau-va-gl
+      mesa
+      nvidia-vaapi-driver
+      nv-codec-headers-12
+    ];
+    extraPackages32 = with pkgs.pkgsi686Linux; [
+      intel-media-driver
+      intel-vaapi-driver
+      vaapiVdpau
+      mesa
+      libvdpau-va-gl
+    ];
+  };
+}