feat(backend): add skeleton discord auth controller

Foxnouns.Backend/Controllers/Authentication/DiscordAuthController.cs

@@ -0,0 +1,14 @@
+using Foxnouns.Backend.Database;
+using Microsoft.AspNetCore.Mvc;
+
+namespace Foxnouns.Backend.Controllers.Authentication;
+
+[Route("/api/v2/auth/discord")]
+public class DiscordAuthController(Config config, DatabaseContext db) : ApiControllerBase
+{
+    [HttpPost("url")]
+    public async Task<IActionResult> AuthenticationUrl()
+    {
+        throw new NotImplementedException();
+    }
+}