rename IndexController, add /version endpoint, and make it visible to swagger

Author: GreemDev

src/Server/Controllers/IndexController.cs

@@ -0,0 +1,36 @@
+using Gommon;
+using Microsoft.AspNetCore.Mvc;
+using Ryujinx.Systems.Update.Server.Helpers;
+
+namespace Ryujinx.Systems.Update.Server.Controllers;
+
+[Route("/")]
+[ApiController]
+public class InfoController : ControllerBase
+{
+    [HttpGet]
+    [ApiExplorerSettings(IgnoreApi = true)]
+    public ActionResult Index() 
+        => Redirect("https://github.com/Ryubing/UpdateServer/");
+
+    [HttpGet("docs"), HttpGet("info"), HttpGet("help")]
+    [EndpointDescription("Redirects the requestor to the /swagger endpoint.")]
+    public ActionResult Help()
+    {
+        return CommandLineState.Swagger
+            ? Redirect("/swagger") 
+            : Index();
+    }
+
+    public static readonly string ServerVersion = typeof(Program).Assembly.GetName().Version!.ToString()[..^2];
+    public const string ReleaseUrlFormat = "https://github.com/Ryubing/UpdateServer/releases/tag/{0}";
+
+    [HttpGet("version")]
+    [EndpointDescription("Redirects to or shows the requestor the current UpdateServer GitHub release URL.")]
+    public ActionResult Version([FromQuery] bool redirect = true)
+    {
+        return redirect
+            ? Redirect(ReleaseUrlFormat.Format(ServerVersion))
+            : Ok(ReleaseUrlFormat.Format(ServerVersion));
+    }
+}