Feature suggestion: Be able to use cache when offline from service workers

[jrosell]

I see that you already use service workers in shinylive. It would be awesome if shinylive could also work offline using the previous loaded cache of the first online connection.

The idea from @udurraniAtPresage is attempted here https://github.com/udurraniAtPresage/shinylive_app, but as we couldn't make it work I build here https://github.com/jrosell/playground4offline a simple example with an offline static html site of what is the goal to achieve with shinylive, if possible.