Add demultiplexer to uSDHC2 for the uSD and WiFi's SDIO interfaces, include the DEMUX's (TS3A27518E) 24QFN footprint

Add MicroSD footprint from selection, add PDF file with searchable/highlightable text

* added footprints

Begin WiFi+BT M.2 socket circuit, connect the associated USB bus from the hub circuit, determined that the i.MX8M's UART's default POR state is such that CTS is an output and RTS is an input and assigned the signals accordingly

Complete more of the USB hub circuit, connect one of the downstream ports to the WWAN M.2 module, remove the unused VBUS rail, add notes regarding the USB-C port having its corresponding ID pin pulled low

Begin USB 2.0 hub circuit for M.2 modules, remove supervisory/voltage monitor/watchdog circuit since the EmCraft SoM implements it

Modify the boot config pins such that the eMMC is an 8-bit bus, depressing a momentary push button switch during boot causes SD boot, and relevant options

Have the charge controller IC handle the USB-C DRP PD switch mechanism, notes added on what procedure is required to operate as sink/source and how to swap between these roles

Include li-ion charge controller PMIC which implements VBAT UVLO, VBAT OVP, input/output OVP & OCP; completely removed the old buck-boost in favor of this fully integrated chip

Add USB type C circuit with DRP PD capability, should sink near 2A @ 5-6.5V and source 550mA @ 5V