Other Adapters: HTML / Slack / WhatsApp

[robmoffat]

It would be great to have an HTML adapter, so that we could have an endpoint exposed via @ChatRequest which conforms to a HTTP request. Then, we would pass the user details through using Spring Security.

We could use this to render Symphony / Teams UI that uses HTML instead of AdaptiveCard / Freemarker. Also, we could pop users out to web pages if they wanted. Finally, this might work quite well for the leader election thing too (?)

[robmoffat]

Having a HTML adapter would potentially solve the issue of displaying forms for WhatsApp.
However, it's a big piece of work.

Another venue for Spring Bot might be slack.

I'm combining all this in this issue as a placeholder.