notes.md

@@ -2,7 +2,8 @@ Let's start C#!
 =================
 
 > **MarkDown 작성법**
-> - Ref. https://gist.github.com/ihoneymon/652be052a0727ad59601
+> - [Ref site](https://gist.github.com/ihoneymon/652be052a0727ad59601)
+> - [Online editor](https://stackedit.io/editor)
 
 ## Glossary