Clarify purpose of `initial_state` option

[nilcolor]

The README shows that I need to include the following in a model:

include Statesman::Adapters::ActiveRecordQueries[
  transition_class: OrderTransition,
  initial_state: :pending
]

And build the machine itself like:

class OrderStateMachine
  include Statesman::Machine

  state :pending, initial: true
  state :checking_out
end

At some point, I was thinking that initial_state option allow to set different initial state for a model that is using the same state machine. But it doesn't. This option also doesn't (right?) work if initial: true is not set. So, why this option is even added? This looks like a constant that can be taken from machine like initial_state: OrderStateMachine.initial_state during initialisation and cannot be changed by a user anyway.
Am I missing something?

[nilcolor]

OK, right. include doesn't pass machine class. So, maybe

include Statesman::Adapters::ActiveRecordQueries[
  transition_class: OrderTransition,
  machine_class: OrderStateMachine
]

? To avoid confusion about multiple initial states (although this is very handy) and also,

def state_machine
  @state_machine ||= OrderStateMachine.new(self, transition_class: OrderTransition,
                                                 association_name: :transitions)
end

can be created for a user...