Guidance for solar-powered installations -- Sleeping Beauty mode for ESP32

[roberthadow]

This probably doesn't require any coding, but some improvement of the documentation would be nice. A walk-though example that achieves the following would help.

USB solar-powered rooftop unit exercises all functions including battery charge during daylight. When battery runs down to below n%, the device suspends all activity except clock and battery monitoring. When battery exceeds n%, device resumes all functions.