added MIT license

[reece]

This PR:

• adds an MIT license and CC0 deed in files LICENSE.txt and LICENSE-CC0.txt respectively
• adds an Availability section in README.md and index.md about licensing and public domain status
• adds a footer declaring CC0

Availability section (similar presentation in index.md on site and README.md on github):

And the footer:

@jtdendunnen @ifokkema @ahwagner

[ahwagner]

This looks good to me. I agree we would also want something to specify that the documentation generated by our site code is available for free reuse. A CC0 public domain attestation in-text would be sufficient IMO.

[ifokkema]

Yes, indeed, we need a license! Some thoughts:

• Placing an MIT license in the repo, and thus the software that generates the site, does not license the output of this software, i.e., the HGVS-nomenclature.org website.
• As such, the website itself also requires a license. I suggest CC-BY-4.0, and placing an icon + link on the website, either in the header somewhere or the footer. Alternatively, we could create a page (e.g., "Terms" or "Legal"), in which we explain the basics and link to the license document.

[reece]

I agree with both of you. I added CC0 to this PR. Please see PR notes at top for details and re-review.

[reece]

@ifokkema and @ahwagner: I accepted your suggestions, made a minor tweak, and copied verbatim to README.md so that they were identical. Please re-review.

[ifokkema]

Great, that works! Looks good to me!

[marinadistefano]

Thanks all. I agree with this license. ClinGen has the same one and I think it makes the most sense.