Phase Hook behavior not fully documented

[jimu]

Phases Documentation should include:

1. the order that hooks are executed
2. the conditions under which they are executed

See

• issue #569 (2020-03-20)
• gitter message

[delucis]

Agreed that these would be very helpful to add — I’m not even 100% clear on order myself.

[delucis]

These tests might be a good place to start:

https://github.com/boardgameio/boardgame.io/blob/7254749886d7b6c1415a5dc2abeccf03260833cf/src/core/flow.test.ts#L1521-L1731

[delucis]