Added a System Design Course (#11462)

Author: Ajay-singh1

courses/free-courses-hi.md

@@ -779,6 +779,7 @@
 
 * [System Analysis and Design](https://www.youtube.com/playlist?list=PLWxTHN2c_6cbuRXdCpsYYMxy0N4SSfIX9) - TJ WEBDEV
 * [System Analysis and Design](https://www.youtube.com/playlist?list=PLi81x6d2Os_8Sa8HifiFruWK6wmgG3Wrg) - Gursimran Singh Dhillon
+* [System Design Playlist](https://www.youtube.com/playlist?list=PLMCXHnjXnTnvo6alSjVkgxV-VH6EPyvoX) - Gaurav Sen
 * [System Design Playlist in Hindi](https://www.youtube.com/playlist?list=PLA3GkZPtsafZdyC5iucNM_uhqGJ5yFNUM) - Engineering Digest
 * [System Design Series By Coding Ninjas](https://www.youtube.com/playlist?list=PLrk5tgtnMN6RvXrfflstJWgcPFQ_vTOV9) - Coding Ninjas