Add system design template link (#433)

README.md

@@ -282,6 +282,7 @@ Check out the following links to get a better idea of what to expect:
 * [How to ace a systems design interview](https://www.palantir.com/2011/10/how-to-rock-a-systems-design-interview/)
 * [The system design interview](http://www.hiredintech.com/system-design)
 * [Intro to Architecture and Systems Design Interviews](https://www.youtube.com/watch?v=ZgdS0EUmn70)
+* [System design template](https://leetcode.com/discuss/career/229177/My-System-Design-Template)
 
 ## System design interview questions with solutions