Document changes and release 56pureos1 into byzantium
* defaults: Improve reliability of bluetooth-brcmfmac against system suspend
* default: ucm2: Move controls to BootSequence where applicable
* librem5-base-defaults: pulse: Bump fragment size up to 24ms
* defaults: librem5-pm: Set devices to suspend after 1.5s and hub after 0.5s
* defaults: librem5-pm: Set readahead based on USB vendor/product ID