added nix flakes

flake.nix

@@ -0,0 +1,41 @@
+# This flake was initially generated by fh, the CLI for FlakeHub (version 0.1.22)
+{
+  description = "Terraria Plugin flake";
+  inputs = {
+    flake-schemas.url = "https://flakehub.com/f/DeterminateSystems/flake-schemas/*";
+    nixpkgs.url = "https://flakehub.com/f/NixOS/nixpkgs/*";
+  };
+  
+  outputs = { self, flake-schemas, nixpkgs }:
+    let
+      supportedSystems = [ "x86_64-linux" "aarch64-darwin" ];
+      forEachSupportedSystem = f: nixpkgs.lib.genAttrs supportedSystems (system: f {
+        pkgs = import nixpkgs { inherit system; };
+      });
+    in {
+      schemas = flake-schemas.schemas;
+
+      devShells = forEachSupportedSystem ({ pkgs }: {
+        default = pkgs.mkShell {
+          packages = with pkgs; [
+            curl
+            git
+            jq
+            wget
+            nixpkgs-fmt
+            dotnet-sdk_9
+            dotnetPackages.Nuget
+            omnisharp-roslyn
+            mono
+          ];
+        };
+
+        env = {
+          DOTNET_ROOT = "${pkgs.dotnet-sdk_9}/share/dotnet";
+          DOTNET_GENERATE_ASPNET_CERTIFICATE = "false";
+          DOTNET_NOLOGO = "true";
+          DOTNET_CLI_TELEMETRY_OPTOUT = "false";
+        };
+      });
+    };
+}