Add support for storage options and execution

[mariobehling]

The hardware has a storage option.

Clarify what additional support is required in the firmware? What can be stored in the storage, e.g. games or animations like snake?

How could a user upload a game or animation? Does the device need to be reflashed in order to do this?

Propose a way to choose games or animations from storage, e.g.

1. User clicks on side button to choose mode (display mode, bluetooth mode, animations and games mode, off)
2. User can use up and down buttons to choose animations or games or exit.