Implement K-NN in Python

[AbhinavShaw09]

This issue is about [Algo/DS Name/Question Name](link to resource for the Algo/DS/Question)

• I searched or browsed the repo’s other issues to ensure this is not a duplicate

• Issue Title is in form [Algo/DS Name] in [Language] (ex:- BubbleSort in Java)

• I will send my PR only after I'm assigned to this issue by any maintainer

• Assign this issue to me (I want to work on this)

• I ensure that I am not already assigned to 2 or more issues

[sobhanbera]

Assigned the issue to you @AbhinavShaw09! You can work on this now!