Add LICENSE file with CC-BY 4.0 license text

[7patricia]

This PR adds a LICENSE file with CC-BY 4.0 license text and adds the CC-BY 4.0 badge to the README file.

[waldyrious]

The MIT license is intended for software. Usually documentation-only repositories like this one tend to use licenses more appropriate for prose. I'd recommend CC-BY 4.0 instead, as it closely mimics the properties of MIT:

CC-BY 4.0 License

Copyright (c) 2016-2019 Uphold

This work is licensed under the Creative Commons Attribution 4.0 International License. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/ or send a letter to Creative Commons, PO Box 1866, Mountain View, CA 94042, USA.

Make this a Markdown file (by adding the .md extension) so that the text is rendered properly, including making the link clickable, as seen above.

You may also add the badge to the README in this PR, with the following code:

[![Creative Commons Attribution 4.0 license][license-badge-image]](license-badge-link)

[license-badge-image]: https://i.creativecommons.org/l/by/4.0/80x15.png
[license-badge-link]: http://creativecommons.org/licenses/by/4.0/

[7patricia]

@waldyrious Updated.

[7patricia]

@waldyrious updated