hardware/edgeconnector.md - Disabling buttons A and B so the pins can be used as general purpose outputs

[martinwork]

https://tech.microbit.org/hardware/edgeconnector/#pins-p5-p11

Under the heading pins: P5, P11 there is a suggestion to disable the buttons by using "delete uBit.buttonA".

For CODAL at least, this doesn't seem to work, but "uBit.buttonA.disable()" does seem to work in C++ as described in lancaster-university/codal-microbit-v2#84 (comment)