Link to development guideline in README [skip ci]

Author: hkalexling

README.md

@@ -130,4 +130,6 @@ Mobile UI:
 
 ## Contributors
 
+Please check the [development guideline](https://github.com/hkalexling/Mango/wiki/Development) if you are interest in code contributions.
+
 [![](https://sourcerer.io/fame/hkalexling/hkalexling/Mango/images/0)](https://sourcerer.io/fame/hkalexling/hkalexling/Mango/links/0)[![](https://sourcerer.io/fame/hkalexling/hkalexling/Mango/images/1)](https://sourcerer.io/fame/hkalexling/hkalexling/Mango/links/1)[![](https://sourcerer.io/fame/hkalexling/hkalexling/Mango/images/2)](https://sourcerer.io/fame/hkalexling/hkalexling/Mango/links/2)[![](https://sourcerer.io/fame/hkalexling/hkalexling/Mango/images/3)](https://sourcerer.io/fame/hkalexling/hkalexling/Mango/links/3)[![](https://sourcerer.io/fame/hkalexling/hkalexling/Mango/images/4)](https://sourcerer.io/fame/hkalexling/hkalexling/Mango/links/4)[![](https://sourcerer.io/fame/hkalexling/hkalexling/Mango/images/5)](https://sourcerer.io/fame/hkalexling/hkalexling/Mango/links/5)[![](https://sourcerer.io/fame/hkalexling/hkalexling/Mango/images/6)](https://sourcerer.io/fame/hkalexling/hkalexling/Mango/links/6)[![](https://sourcerer.io/fame/hkalexling/hkalexling/Mango/images/7)](https://sourcerer.io/fame/hkalexling/hkalexling/Mango/links/7)