For anyone wanting to build the demo package and found problems like I did. Don't download the release. instead download this repo. Make the appropriate changes for WebGL build and the tutorial will work perfectly.
You can also just try the link in the documentation and download the 1.0.1 version which says "Fixed the demo scene". I have deleted the old 1.0.0 version just so we avoid further confusion with other participants. But yes downloading the repo also works. Good work!
