Improve persistence documentation

[Daanielvb]

Hello, I am using the JPARepositoryInterface to persist my state machine and noticed that a list of tables is generated (state machine, guards, actions, transitions and so on). During initial tests, I only see the state machine table populated and would like to know which tables are the minimum required to have the framework working as expected.

PS: I don't intend to create dynamic machines based off the DB configurations for now