docs/esp32: Add a note to quickref about use of Pin.PULL_HOLD.
@@ -161,6 +161,9 @@ Notes:
* Pins 34-39 are input only, and also do not have internal pull-up resistors
+* The pull value of some pins can be set to ``Pin.PULL_HOLD`` to reduce power
+ consumption during deepsleep.
+
PWM (pulse width modulation)
----------------------------
