Move overlays into a module

overlays/default.nix

@@ -0,0 +1,52 @@
+{ pkgs, ... }:
+
+{
+  nixpkgs = {
+    config.allowUnfree = true;
+
+    overlays = [
+      prismlauncher.overlays.default
+      nur.overlay
+
+      (self: super: {
+
+        tela-icon-theme = super.tela-icon-theme.overrideAttrs (old: {
+          src = inputs.tela-icon-theme;
+        });
+
+        prismlauncher = super.prismlauncher.overrideAttrs (old: {
+          patches = (old.patches or []) ++ [
+            inputs.prism-game-options-patch
+            inputs.prism-ftb-patch
+          ];
+        });
+
+        libadwaita = super.libadwaita.overrideAttrs (old: {
+          patches = (old.patches or []) ++ [
+            ./patches/adwaita-theming-support.patch
+          ];
+          doCheck = false;
+        });
+
+        discord = (super.discord.overrideAttrs (old: {
+          desktopItem = old.desktopItem.override (old: { exec = old.exec + " --disable-gpu-sandbox"; });
+        })).override {
+          withOpenASAR = true;
+          withVencord = true;
+          withTTS = true;
+        };
+
+        catppuccin-plymouth = super.catppuccin-plymouth.override {
+          variant = "frappe";
+        };
+      })
+    ];
+  };
+
+  home-manager = {
+    useGlobalPkgs = true;
+    useUserPackages = true;
+  };
+
+  system.stateVersion = "23.05";
+}