docs/packages: Add quick "Creating distribution packages" section.
docs/packages: Add quick "Creating distribution packages" section.

Needs more details.

henriknelson/micropython,adafruit/micropython,tralamazza/micropython,tralamazza/micropython,pfalcon/micropython,MrSurly/micropython,adafruit/micropython,tobbad/micropython,MrSurly/micropython,adafruit/micropython,ryannathans/micropython,tobbad/micropython,adafruit/micropython,infinnovation/micropython,ryannathans/micropython,henriknelson/micropython,pramasoul/micropython,bvernoux/micropython,adafruit/circuitpython,pozetroninc/micropython,tobbad/micropython,trezor/micropython,blazewicz/micropython,infinnovation/micropython,swegener/micropython,infinnovation/micropython,trezor/micropython,dmazzella/micropython,adafruit/micropython,dmazzella/micropython,selste/micropython,pramasoul/micropython,swegener/micropython,pfalcon/micropython,blazewicz/micropython,adafruit/circuitpython,bvernoux/micropython,kerneltask/micropython,henriknelson/micropython,MrSurly/micropython,infinnovation/micropython,blazewicz/micropython,dmazzella/micropython,adafruit/circuitpython,MrSurly/micropython,trezor/micropython,trezor/micropython,swegener/micropython,tobbad/micropython,ryannathans/micropython,infinnovation/micropython,kerneltask/micropython,ryannathans/micropython,pfalcon/micropython,adafruit/circuitpython,pozetroninc/micropython,kerneltask/micropython,tralamazza/micropython,pramasoul/micropython,ryannathans/micropython,selste/micropython,pfalcon/micropython,henriknelson/micropython,swegener/micropython,dmazzella/micropython,adafruit/circuitpython,pozetroninc/micropython,swegener/micropython,kerneltask/micropython,bvernoux/micropython,pozetroninc/micropython,selste/micropython,selste/micropython,adafruit/circuitpython,blazewicz/micropython,MrSurly/micropython,pramasoul/micropython,bvernoux/micropython,henriknelson/micropython,pfalcon/micropython,selste/micropython,tobbad/micropython,pramasoul/micropython,bvernoux/micropython,pozetroninc/micropython,tralamazza/micropython,trezor/micropython,blazewicz/micropython,kerneltask/micropython