Update free-courses-hi.md (#4494)

* Update free-courses-hi.md

Added Data Structures, and made some structural changes according to the guidelines.

* Update free-courses-hi.md

Updated the links in the Data Structures Topic.

* Update free-courses-hi.md

free-courses-hi.md

@@ -2,7 +2,9 @@
 
 * [C](#C)
 * [C++](#C++)
+* [Data Structures](#DataStructures)
 * [Java](#Java)
+* [Python](#Python)
 
 
 ### C
@@ -15,6 +17,13 @@
 * [The Complete C++ Course | Hindi](https://www.youtube.com/playlist?list=PLLYz8uHU480j37APNXBdPz7YzAi4XlQUF) - Saurabh Shukla
 
 
+### Data Structures
+
+* [All Data Structure Concepts | Hindi](https://www.youtube.com/playlist?list=PLsFNQxKNzefJNztGGoQC-59UhSwIaiIW3) - Saurabh Shukla
+* [All Sorting algorithms and Programs | Hindi](https://www.youtube.com/playlist?list=PLsFNQxKNzefJU-Sj__mljvrmJHZVKWbEm) - Saurabh Shukla
+* [Data Structure Programs | Hindi](https://www.youtube.com/playlist?list=PLsFNQxKNzefK_DAUwnQwBizOmcY7aDLoY) - Saurabh Shukla
+
+
 ### Java
 
 * [The complete Java tutorial | Hindi](https://www.youtube.com/playlist?list=PLu0W_9lII9agS67Uits0UnJyrYiXhDS6q) - Harry
@@ -22,9 +31,9 @@
 
 ### Python
 
-* [Python Tutorial For Beginners In Hindi (With Notes)](https://www.youtube.com/watch?v=gfDE2a7MKjA) - Harry
+* [Python Tutorial For Beginners | Hindi (With Notes)](https://www.youtube.com/playlist?list=PLu0W_9lII9agICnT8t4iYVSZ3eykIAOME) - Harry
 
 
 ### JavaScript
 
-* [JavaScript Tutorial In Hindi](https://www.youtube.com/watch?v=hKB-YGF14SY) - Harry
+* [JavaScript Tutorial | Hindi](https://www.youtube.com/playlist?list=PLu0W_9lII9ajyk081To1Cbt2eI5913SsL) - Harry