Introducing Multiple Default Peers per User

[ReeseWang]

I've introduced two new configuration options: default_peers_per_user and default_peer_names. Now, when a user is created, the program will automatically generate a number of peers specified by default_peers_per_user. Should default_peers_per_user exceed the number of names provided in default_peer_names, the program will revert to the existing naming convention for any additional peers.

Should this enhancement be approved, I plan to update the documentation accordingly within this pull request.

To maintain compatibility with existing setups, I've set default_peers_per_user to default to 1. Furthermore, I've retained the create_default_peer option for now, although it could potentially be phased out. In the future, simply setting default_peers_per_user to 0 could serve as the indicator for whether or not peers should be created.

[h44z]

In principle, this sounds OK, but we need to update the documentation to describe this feature. Also, remove the create_default_peer configuration option (as v2 is not yet finally released, this breaking change is fine for me).