Added Huffman Coding Problem

[pratikscfr]

Description

Added a solution to famous Huffman Coding Problem, which is a greedy algorithm.

Fixes # (issue)

Type of change

Please delete options that are not relevant.

• New feature/question

Checklist:

• My code follows the style guidelines of this project i.e. Pep8
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• Any dependent changes have been merged and published in downstream modules
• I have squashed unnecessary commits

[prabhupant]

Please write a brief description of the question and solution as a docstring. Also, use 4 spaces for identation

[pratikscfr]

Changes added to the code according to format.