Remove containers

[mweidner037]

Containers are convenient but too constraining. We should instead improve the network + storage support for regular apps (https://github.com/composablesys/collabs/issues/241) and make an easy testing tool to replace container-testing-server.

[mweidner037]

• [ ] Deprecate both packages
• [ ] Guide updates
• [ ] Better WebSocketServer: ask clients for saves that trim the log (e.g. every 100 updates/30 seconds); handle that you can use to store/load docs; notion of “room”; see y-websocket; command to run it, in place of container-testing-server.
• [ ] Delete old template. Update standalone template to work out of the box with WebSocketServer (simple command that works once you set up Webpack or whatever, to replace container-testing-server).
  • [ ] “Connected” checkbox like currently. Don’t need send/receive distinction; persist state across refreshes.
• [ ] Remove horse-color-genetics single file version. Redirect old multi-file URL to wherever it ends up.
• [ ] Remove container-dependent demos (selector; ??)
• [ ] Rewrite Matrix instructions (server index.html?)