Update README.md

203059004-pa3/README.md

 References :
 1. https://www.codesdope.com/course/data-structures-avl-trees/
    AVL Tree Psuedocode and Implementation - Iterative implementation of AVL tree
-   I first worked with recursive implementation which is fairly intuitive and easy to code, but
-   couldn't get deletion to work. I switched to the iterative implementation present on the above link 
-   and after some modifications, was able to get both insertion and deletion to work.
-   I am not sure whether this is allowed as per plagiarism rules, but due to time constraints, I wasn't 
-   able to implement AVL tree from scratch. If this violates plagiarism rules, please ignore my 
-   submission for mm2.c .
 
 2. http://www.cs.cmu.edu/afs/cs/academic/class/15213-s12/www/lectures/19-allocation-advanced-1up.pdf
    For understanding of explicit lists with boundary tag method for coalescing.