added SystemDesign in index and two courses in it in free-courses-hi.md (#7332)

* added SystemDesign in index and two courses in it

* Update free-courses-hi.md

* adding Software Engineering and a course in it

* blank-spaces removed

* Update free-courses-hi.md

* Update courses/free-courses-hi.md

Co-authored-by: David Ordás <3125580+davorpa@users.noreply.github.com>

* Update courses/free-courses-hi.md

Co-authored-by: David Ordás <3125580+davorpa@users.noreply.github.com>

* Update courses/free-courses-hi.md

Co-authored-by: David Ordás <3125580+davorpa@users.noreply.github.com>

Co-authored-by: David Ordás <3125580+davorpa@users.noreply.github.com>

courses/free-courses-hi.md

@@ -35,6 +35,8 @@
 * [Ruby](#ruby)
     * [Ruby on Rails](#ruby-on-rails)
 * [Rust](#rust)
+* [Software Engineering](#software-engineering)
+* [System Design](#system-design)
 
 
 ### Algorithms
@@ -311,3 +313,15 @@
 ### Rust
 
 * [Rust Complete Tutorial In Hindi](https://www.youtube.com/playlist?list=PLRuqvIc0eAmp8Lv6M4BKQWEinvCuqdVFP) - One Two Coding
+
+
+### Software Engineering
+
+* [Software Engineering](https://www.youtube.com/playlist?list=PLxCzCOWd7aiEed7SKZBnC6ypFDWYLRvB2) - Gate Smashers
+
+
+### 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
+