ADD: Morris Traversal

[SatyamThakur0]

Morris Traversal is an efficient algorithm for in-order traversal of a binary tree that doesn't require additional space for a stack or recursion. Instead, it temporarily modifies the tree structure to create links between nodes, and at the end it restores the original form of the tree.

@Vanshikapandey30, I hope you will assign me to contribute this code to this repo.

And also, please add the hectoberfest tag.

[Satyam-nitp]

can you assign this to me @Vanshikapandey30