usb_serial_jtag.h is not in Programming Guide

[jmadsenee]

There is no information on usb_serial_jtag.h functions in the ESP-IDF Programming Guide. I can search for and find functions like uart_write_bytes() in uart.h, but if I search on usb_serial_jtag_ functions they do not come up. I can find usb_serial_jtag_ functions in the examples and figure most of it out, but when will it be added to the Programming Guide?