Show the restrictions on the confirmation

[esigler]

It'd be helpful to users if a confirmation would show the types of approvers allowed. In the current behavior:

This command requires confirmation. To confirm, send the command "confirm abc123"

it's less than clear if I can self-confirm, or how long I have to confirm, etc. One possible alternative would be:

defaults

This command requires confirmation. Approvers include: anyone.  To confirm, send the command "confirm abc123" within the next 60 seconds.

restrict_to: :managers

This command requires confirmation. Approvers include: users in the "managers" group.  To confirm, send the command "confirm abc123" within the next 60 seconds.

allow_self: false

This command requires confirmation. Approvers include: anyone other than yourself.  To confirm, send the command "confirm abc123" within the next 60 seconds.