Demo page link doesn't work

[RichardDavies]

The demo page linked at the top of the project's Readme.md no longer works. I was able to find an archived version, but you should consider publishing a new demo page somewhere.

https://web.archive.org/web/20180626012005/http://humaan.com/modaal/

Also, there's a typo in the readme at the end of section 2.3. data-overlay-opacity="0.8" should be data-modaal-overlay-opacity="0.8"