Improve schematic and pcb (add snubber network to driver output)

Some changes to the step down converter, Fix #8

Some little cleanups

Fix #13

Little update

Fix schematic error described in #8

Fix #7

Some little improvements

Remove connection to SLEEPn Pin I think we don't have to connect this pin, and if yes we can fix it manually on the prototype The support of Alegro wasn't very helpful about that topic

Improve BOM