added Compiler design in index and a course in it in free-courses-hi.md (#7317)

* added ComputerArchitecture in index and a course in it

* added compiler design and one course in it

courses/free-courses-hi.md

@@ -7,6 +7,8 @@
 * [Blockchain](#blockchain)
 * [C](#c)
 * [C++](#cpp)
+* [Compiler Design](#compiler-design)
+* [Computer Organization and Architecture](#computer-organization-and-architecture)
 * [Data Structures](#data-structures)
 * [DevOps](#devops)
 * [Flutter](#flutter)
@@ -90,6 +92,16 @@
 * [The Complete C++ Course \| Hindi](https://www.youtube.com/playlist?list=PLLYz8uHU480j37APNXBdPz7YzAi4XlQUF) - Saurabh Shukla
 
 
+### Compiler Design
+
+* [Compiler Design (Complete Playlist)](https://www.youtube.com/playlist?list=PLxCzCOWd7aiEKtKSIHYusizkESC42diyc) - Gate Smashers (YouTube)
+
+
+### Computer Organization and Architecture
+
+* [Computer Organization and Architecture](https://www.youtube.com/playlist?list=PLxCzCOWd7aiHMonh3G6QNKq53C6oNXGrX) - Gate Smashers (YouTube)
+
+
 ### Data Structures
 
 * [2-D Arrays - Level 1](https://www.youtube.com/playlist?list=PL-Jc9J83PIiFkOETg2Ybq-FMuJjkZSGeH) - Pepcoding