Adding Kahn's Algorithm

[Akshat293]

I want to add Kahn's Algorithm in Graphs Folder
please assign me this issue:

[github-actions]

Thanks for creating your' first issue

[siddharth25pandey]

@Tom635 Assigned.
Go ahead 👍

[navjotdadwal]

Sir please assign this issue to me

Why you should assign this to me?
i am current rated 5 star at codechef with rating of 2153 and rated expert at codeforces with rating of 1776
https://codeforces.com/profile/navjotdadwal
https://www.codechef.com/users/navjot1234
So i can handle and solve this issue

[shubhankar-shandilya-india]

Sir please assign me this issue i know how kahn's algorithm

[asv02]

@siddharth25pandey ,I can add a very well-explained code for this question, please assign it to me under hacktoberfest label.