[website] Add playground

[wkozyra95]

Release blockers:

• Add a way to configure connecting to local compositor instance in development and to production when deployed
• Improve experience when the server is not accessible, or under heavy load (maybe retry request, make sure timeouts are configured, ...)
• The request queue should handle the latest request and drop it if the request is too long in the queue.
• Add some relatively complex scene that make sense (represents some sensible layout that looks "real")
• Add local storage (and way to reset to default or one of the examples)

Lower priority:

• [ ] Add support for generating MP4 output (10 second clips)
  • [ ] Generate input streams (input stream name + timer, the same as in docs)
  • [ ] Create new endpoint to run those renderers (leave old endpoint as it is)
• Generate example inputs as MP4 (they will be used by WASM implementation)