[Suggestion] Channel Directory / Channel Topics

It might be possible to do this with a bot (though I can't say I've found one yet), but I think that ideally this might actually be a nice channel type/option. A channel directory. 

A channel directory would be a channel that would be automatically created and updated which lists all of the other channels in the discord including the Categories AND Channel Topic. Right now, we can only use the # to put the channel name, but we don't have a way to list the channel topic right now, without hand typing this information after it. It would be nice if it was possible to just auto generate this summary list and have it linked so it live updates. 

While channel directories aren't something I see used in many servers right now, they are extremely helpful. The only issue you would have that might interfere with this, will be permissions because some channels will not be visible to all ranks. 

If this isn't possible to easily do due to permission issues, it would be nice if we at least had a way to automatically list not only the channel, but also the channel topic, in a manor that is linked to avoid having to manually update this information

As another alternative, it may be nice if the channel topic could be listed when you mouse over. This would however only work on the website and not the app

Thanks!