Linked List Problems are missing

[AbhishekCS3459]

@tarunsinghdev Although I solved more than half of the DSA problem of Love Babbar, I want to contribute for it. I had many efficient solution for the DSA sheet solution.

[tarunsinghdev]

Hey, sure you can contribute with your solutions. For missing problems, you can always create a topic folder and add your solutions to it. In your case, you can create a Linked List folder at the root and can start contributing.
Also, make sure you update the README.md for the same.

[RoyalBosS-Ayush]

Added linkedlist solution in this PR
Can you Merge it and add Hacktoberfest accepted label?