Improve editiability and visibility of Chat channel descriptions

[mcwumbly (Dave McClure)]

This should be improved now with the information panel:

@rishabh

Chat Information panel

Clicking a channel title will now take users to a useful info panel with three tabs:

• The About tab will display title, description and linked category, so users have the context they need for each channel.
• The Members tab lets users see who else is in the room with them (member list and total count). It includes a filter so they can use search.

• The Settings tab will let you set notification preferences (mute, desktop / mobile push notifications). For admins, this tab also includes the auto-join mode toggle.