add NOTICE

huan · huan · commit 9bb7a67b84cc · 2020-05-22T12:14:28.000+08:00
diff --git a/NOTICE b/NOTICE
@@ -0,0 +1,8 @@
+Go Wechaty Chatbot SDK
+Copyright 2020 Wechaty Contributors.
+
+This product includes software developed at
+The Wechaty Organization (https://github.com/wechaty).
+
+This software contains code derived from the Stackoverflow,
+including various modifications by GitHub.
