Add README for heap

[shubhamprk175]

Resolves #43

[shubhamprk175]

@SiddharthaAnand Can you please have a look at this?
Also on the hactoberfest website, my PR is being shown as ineligible. The reason being:

1. Either the repo is labeled with "hackoberfest"
2. Or the particular PR is labeled as "hacktoberfest-accepted"

[shubhamprk175]

@SiddharthaAnand It's really disappointing for an open-source newcomer to genuinely contribute to a repo and get ignored. I remember you preaching someone about the values of the open-source community on some other PR. But not acknowledging someone's contribution to the community is I guess not a good portrayal of your sincerity towards the community. You are very well aware that it's Hactoberfest time, lots of genuine newcomers would be contributing to repos. And here you are ignoring a PR for 19 days. It's really discouraging SIR.