Ambiguity about powering the Touch Display

[lurch]

@jackbenwillis noticed that when connecting the Touch Display to a Raspberry Pi, you then have two micro-USB power-input sockets (one on the Pi, one on the Display) and https://www.raspberrypi.com/documentation/accessories/display.html doesn't explain which one you should use. He asked some engineers, and got told "you can use either, but because Pi 4 requires more power the official line should be to power the Pi not the touch display", so we should reflect that in the documentation.

[aallan]

I just looked at the the documentation on the Touch Display and it needs totally overhauling. The page is a bit of a relic.

[github-actions]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[aallan]

Still needs doing.