Update system design courses (#8537)

* Update free-courses-hi.md

* Update free-courses-en.md

courses/free-courses-en.md

@@ -87,6 +87,7 @@
 * [Spark](#spark)
 * [Swift](#swift)
     * [Vapor](#vapor)
+* [System Design](#system-design)
 * [Terraform](#terraform)
 * [Theory](#theory)
 * [TypeScript](#typescript)
@@ -362,7 +363,6 @@
 * [MIT's Introduction to Computer Science and Programming](https://ocw.mit.edu/courses/electrical-engineering-and-computer-science/6-00sc-introduction-to-computer-science-and-programming-spring-2011/) - John Guttag (MIT OpenCourseWare)
 * [MIT's Introduction to Computer Science and Programming in Python](https://ocw.mit.edu/courses/electrical-engineering-and-computer-science/6-0001-introduction-to-computer-science-and-programming-in-python-fall-2016/) - Ana Bell, Eric Grimson, John Guttag (MIT OpenCourseWare)
 * [MIT's Mathematics for Computer Science](http://ocw.mit.edu/courses/electrical-engineering-and-computer-science/6-042j-mathematics-for-computer-science-fall-2010/video-lectures/)
-* [System Design](https://www.youtube.com/playlist?list=PLMCXHnjXnTnvo6alSjVkgxV-VH6EPyvoX) - Gaurav Sen
 
 
 ### Cuda
@@ -1212,6 +1212,12 @@
 * [Vapor University](https://vapor.university)
 
 
+### System Design
+
+* [System Design](https://www.youtube.com/playlist?list=PLMCXHnjXnTnvo6alSjVkgxV-VH6EPyvoX) - Gaurav Sen
+* [System Design Primer Course](https://www.youtube.com/playlist?list=PLTCrU9sGyburBw9wNOHebv9SjlE4Elv5a) - sudoCODE
+
+
 ### Terraform
 
 * [terraform + AWS](https://www.udemy.com/course/terraform-aws) - Rohit Abraham (Udemy)

courses/free-courses-hi.md

@@ -452,4 +452,3 @@
 
 * [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 Primer Course](https://www.youtube.com/playlist?list=PLTCrU9sGyburBw9wNOHebv9SjlE4Elv5a) - sudoCODE