Create a glitch project we can easily remix to change the scene

[vincentfretin]

Create a glitch project we can easily remix to change the scene.
Mainly based on the playground/index.html but with enter screen by default, without the help box.
To be done once the ui components in #34 are done.

[uhunkler]

Such a Glitch project will surely help others to start and experiment with transforming their Hubs scenes. Remix the project, drag the GLB onto the browser window, done ;-)