Update free-courses-hi.md (#10759)

* Update free-courses-hi.md

* Update free-courses-hi.md

* Update free-courses-hi.md

courses/free-courses-hi.md

@@ -83,6 +83,7 @@
 * [Dynamic Programming Playlist \| Coding \| Interview Questions \| Tutorials \| Algorithm](https://www.youtube.com/playlist?list=PL_z_8CaSLPWekqhdCPmFohncHwz8TY2Go) - Aditya Verma
 * [Dynamic Programming Workshop](https://www.youtube.com/playlist?list=PLqf9emQRQrnKA_EeveiXQj_uP25w8_5qL) - Vivek Gupta
 * [Generic Trees - Level 1](https://www.youtube.com/playlist?list=PL-Jc9J83PIiEmjuIVDrwR9h5i9TT2CEU_) - Pepcoding
+* [Graph Theory](https://www.youtube.com/playlist?list=PLxCzCOWd7aiG0M5FqjyoqB20Edk0tyzVt) - Gate Smashers
 * [Graphs - Level 1](https://www.youtube.com/playlist?list=PL-Jc9J83PIiHfqDcLZMcO9SsUDY4S3a-v) - Pepcoding
 * [Hindi Data Structures And Algorithms Tutorial Python](https://www.youtube.com/playlist?list=PLPbgcxheSpE3NlJ30EDpxNYU6P2Jylns8) - codebasics Hindi
 * [Linked List - Level 1](https://youtube.com/playlist?list=PL-Jc9J83PIiF5VZmktfqW6WVU1pxBF6l_&si=S_MRPF7yyupBUCC6) - Pepcoding