Add support for Twilight gateway queue

Myriad/Gateway/Limit/TwilightGatewayRatelimiter.cs

@@ -0,0 +1,27 @@
+using System.Net.Http;
+using System.Threading.Tasks;
+
+using Serilog;
+
+namespace Myriad.Gateway.Limit
+{
+    public class TwilightGatewayRatelimiter: IGatewayRatelimiter
+    {
+        private readonly string _url;
+        private readonly ILogger _logger;
+        private readonly HttpClient _httpClient = new();
+        
+        public TwilightGatewayRatelimiter(ILogger logger, string url)
+        {
+            _url = url;
+            _logger = logger;
+        }
+
+        public async Task Identify(int shard)
+        {
+            // Literally just request and wait :p
+            _logger.Information("Shard {ShardId}: Requesting identify at gateway queue {GatewayQueueUrl}", shard, _url);
+            await _httpClient.GetAsync(_url);
+        }
+    }
+}