Clearer instructions. Example only works if you load it onto a webserver

Created by: JaapHaitsma

Had some issues to get it to work. Chrome throws an error in the dev console if you load dash.js/index.html on the local file system.

Just discovered that dash.js is hosted on http://dashif.org/reference/players/javascript/index.html I suggest you add that als such that people can easily try it out