Rename README.md to About.md

[debmalya]

This is an interesting project. Found empty README.md. What is the content of this About.md like to add in README.md.

[googlebot]

Thanks for your pull request. It looks like this may be your first contribution to a Google open source project. Before we can look at your pull request, you'll need to sign a Contributor License Agreement (CLA).

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[debmalya]

I signed it!

[googlebot]

CLAs look good, thanks!

[debmalya]

If allowed want to add the contents of About.md to README.md