Document what feature interfaces are typically available in HttpContext.Features and ConnectionContext.Features

[halter73]

@mconnew Pinged me recently asking "How do I get the remote client IP address from ConnectionContext?". This was for 2.1 before you could get this directly from the ConnectionContext. It highlighted how ConnectionContext Features, and by extension HttpContext Features, aren't very discoverable. I think a good doc could help with this.

[estebarbms]

Any update on this one? Actually I'm looking for getting the remote client IP from a ConnectionContext too

[JamesNK]

Request features are covered here: https://learn.microsoft.com/en-us/aspnet/core/fundamentals/request-features?view=aspnetcore-6.0

(I think the list should be changed to a table)

Could add something similar for connection features.