Add Greedy and Tree Algorithms

[Soumya1219]

Description of the problem

Adding Minimum Spanning Tree algorithms and Greedy Algorithms which are best practices for data structure and algorithms in Python

Example of the problem

Kruskal's Algorithm
Prim's Algorithm
Huffman Code
Activity Selection Problem

References/Other comments

I have good grip in data structures and algorithms and I have very good knowledge and experience in Python Programming so I can contribute for this issue.

[Soumya1219]

@Carreau Kindly assign me with this issue :)

[Meghaa702]

please assign me this issue. I really want to contribute.