Support for kiosk-like experiences

It's now possible to use Ready Player Me in kiosk-like environments where multiple people are creating avatars using the same device, for instance, during conference demos.

If the `?clearCache=true` query parameter is present, page reloads cause the avatar creation to start from step 1.

`https://demo.readyplayer.me/avatar?clearCache=true`

This is part of a series of WebAPI improvements coming to Ready Player Me, enabling you to have more control over your integration.

Check out the documentation for more information.