Include Documentation for Migrating from 0.9.x to 1.0

docs/guides/samples/migrating/event.cs

@@ -0,0 +1,4 @@
+_client.MessageReceived += async (msg) =>
+{
+    await msg.Channel.SendMessageAsync(msg.Content);
+}

docs/guides/samples/migrating/sync_event.cs

@@ -0,0 +1,5 @@
+_client.Log += (msg) =>
+{
+    Console.WriteLine(msg.ToString());
+    return Task.CompletedTask;
+}

docs/guides/terminology.md

@@ -1,3 +1,8 @@
+---
+uid: Terminology
+title: Terminology
+---
+
 # Terminology
 
 ## Preface