add usage guide

README.md

@@ -1,6 +1,40 @@
 # Wowzers what a cool website!
 Source code for da website o_O
 
+### Using
+First add a the wa2k flake as an input:
+```nix
+# in flake.nix
+inputs = {
+  wa2k = {
+    # url = "git+https://tearforge.net/cry/wa2k.com";
+    url = "/home/me/test/wa2k";
+    inputs = {
+      systems.follows = "systems";
+      nixpkgs.follows = "nixpkgs";
+    };
+  };
+};
+```
+
+Then ensure `wa2k.nixosModules.default` is imported and `wa2k.overlays.default` is used:
+```nix
+# in configuration.nix
+imports = [
+  inputs.wa2k.nixosModules.default
+];
+
+nixpkgs.overlays = [
+  inputs.wa2k.overlays.default
+];
+
+services.wa2k = {
+  enable = true;
+  port = 8080;
+  openFirewall = true;
+};
+```
+
 ### Local Development
 >[!WARNING]
 > This project is packaged using Nix, it's easier to work it this way :3