✨ Setup etcd helper and magic onion

DysonNetwork.Shared/Etcd/IEtcdService.cs

@@ -0,0 +1,13 @@
+using System;
+using System.Collections.Generic;
+using System.Threading.Tasks;
+
+namespace DysonNetwork.Shared.Etcd
+{
+    public interface IEtcdService : IDisposable
+    {
+        Task RegisterServiceAsync(string serviceName, string serviceAddress, int ttl = 15);
+        Task UnregisterServiceAsync();
+        Task<List<string>> DiscoverServicesAsync(string serviceName);
+    }
+}