Add jumper to JP1 external power jumper

[nseidle]

To make it easier to swap back and forth

[alwaysAn0n]

This would be very useful. I can't imagine why it doesn't ship with one.

[ReneElizondo]

Yes please, that would be incredible useful, but please don't stop there, you should also add jumpers to the antenna select so that its easy to switch between the external and internal antenna.