Flipswitch: Update documentation from classes option changes

[cgack]

The PR 8118 has changed the way the flipswitch will work for 1.5 due to implementation of classes option. The API docs will need to reflect the updated version.

[agcolom]

@cgack I'm adding a 1.5 milestone label. Is this correct? Thanks

[cgack]

@agcolom yes indeed. Thanks!