Unable to set digital pins to INPUT_PULLUP

[henrygab]

For a digital pin, the UI only allows to toggle between "INPUT" and "OUTPUT".

For pins which support the pullup resistor, the UI needs to enable a three-way choice:

• INPUT
• OUTPUT
• INPUT_PULLUP

Better yet, just list the pins, each with a distinct drop-down for the types of use they have.

The INPUT_PULLUP option is necessary to allow validation of functionality on boards that rely on the internal pullup resistors (e.g., many common designs that use push button / momentary switches).