Make `PublishError.InsufficientPeers` a bit more self-explanatory?

[achingbrain]

A recurring question that comes up is:

I get PublishError.InsufficientPeers but I have plenty of peers, what gives?

The error does not mean you don't have peers, it means you don't have any peers listening on the pubsub topic you are trying to publish on.

If this was changed to PublishError.InsufficientTopicPeers or even something like PublishError.InsufficientPeersSubscribedToTopic it might be a bit clearer for people?