Update instructions page (readme.md)

[rocketinventor]

The Readme only has instructions for running using make and seems a little bit outdated.
There is no reference to the JS version at all. I would like to propose adding a mention to the JS version. I would also like to propose suggesting that one can test out the JS version easily with RawGit. Also, I would add the instruction you wrote on the JS version itself: "If you are opening this file locally (file://), Chrome will give you errors. Try using php -S localhost:8000 or similar for a quick web server."

[fulldecent]

Thank you, updated

[rocketinventor]

@fulldecent Please Fix the link for the JS version.
On rawgit.com:
"Use a specific tag or commit hash in the URL (not a branch). Files are cached permanently based on the URL. Query strings are ignored. I have provided the proper urls in a comment. Please see my comment on the commit.
Thanks!