docs/esp8266/quickref: Update information on SPI classes.
docs/esp8266/quickref: Update information on SPI classes.

SPI(1) is not used for hardware SPI. Few more details are provided.

SHA2017-badge/micropython-esp32,hiway/micropython,Peetz0r/micropython-esp32,hiway/micropython,SHA2017-badge/micropython-esp32,mhoffma/micropython,Timmenem/micropython,torwag/micropython,jmarcelino/pycom-micropython,jmarcelino/pycom-micropython,matthewelse/micropython,lowRISC/micropython,dxxb/micropython,bvernoux/micropython,kerneltask/micropython,swegener/micropython,dmazzella/micropython,tobbad/micropython,pozetroninc/micropython,PappaPeppar/micropython,mhoffma/micropython,micropython/micropython-esp32,adafruit/circuitpython,HenrikSolver/micropython,adafruit/circuitpython,turbinenreiter/micropython,MrSurly/micropython,oopy/micropython,adafruit/micropython,trezor/micropython,PappaPeppar/micropython,adafruit/micropython,AriZuu/micropython,kerneltask/micropython,cwyark/micropython,henriknelson/micropython,HenrikSolver/micropython,torwag/micropython,chrisdearman/micropython,adafruit/circuitpython,pramasoul/micropython,mhoffma/micropython,dmazzella/micropython,hosaka/micropython,ryannathans/micropython,tobbad/micropython,ryannathans/micropython,micropython/micropython-esp32,AriZuu/micropython,selste/micropython,Peetz0r/micropython-esp32,deshipu/micropython,tuc-osg/micropython,dmazzella/micropython,toolmacher/micropython,toolmacher/micropython,torwag/micropython,deshipu/micropython,MrSurly/micropython-esp32,trezor/micropython,lowRISC/micropython,AriZuu/micropython,oopy/micropython,jmarcelino/pycom-micropython,MrSurly/micropython-esp32,TDAbboud/micropython,mhoffma/micropython,turbinenreiter/micropython,tuc-osg/micropython,pozetroninc/micropython,SHA2017-badge/micropython-esp32,MrSurly/micropython-esp32,MrSurly/micropython-esp32,alex-robbins/micropython,HenrikSolver/micropython,dxxb/micropython,dxxb/micropython,pramasoul/micropython,torwag/micropython,jmarcelino/pycom-micropython,HenrikSolver/micropython,ryannathans/micropython,pramasoul/micropython,kerneltask/micropython,MrSurly/micropython,dxxb/micropython,torwag/micropython,kerneltask/micropython,lowRISC/micropython,TDAbboud/micropython,toolmacher/micropython,Timmenem/micropython,blazewicz/micropython,cwyark/micropython,pfalcon/micropython,jmarcelino/pycom-micropython,chrisdearman/micropython,chrisdearman/micropython,SHA2017-badge/micropython-esp32,TDAbboud/micropython,pfalcon/micropython,infinnovation/micropython,hiway/micropython,infinnovation/micropython,alex-robbins/micropython,deshipu/micropython,alex-march/micropython,puuu/micropython,oopy/micropython,pfalcon/micropython,blazewicz/micropython,Peetz0r/micropython-esp32,trezor/micropython,pozetroninc/micropython,PappaPeppar/micropython,micropython/micropython-esp32,micropython/micropython-esp32,AriZuu/micropython,adafruit/micropython,turbinenreiter/micropython,swegener/micropython,MrSurly/micropython,bvernoux/micropython,kerneltask/micropython,adafruit/circuitpython,tralamazza/micropython,hosaka/micropython,bvernoux/micropython,PappaPeppar/micropython,selste/micropython,puuu/micropython,chrisdearman/micropython,Timmenem/micropython,tuc-osg/micropython,trezor/micropython,Peetz0r/micropython-esp32,pramasoul/micropython,matthewelse/micropython,matthewelse/micropython,hiway/micropython,Peetz0r/micropython-esp32,hiway/micropython,pfalcon/micropython,MrSurly/micropython,puuu/micropython,lowRISC/micropython,deshipu/micropython,TDAbboud/micropython,toolmacher/micropython,dmazzella/micropython,micropython/micropython-esp32,dxxb/micropython,lowRISC/micropython,adafruit/micropython,alex-robbins/micropython,pozetroninc/micropython,tobbad/micropython,turbinenreiter/micropython,bvernoux/micropython,matthewelse/micropython,selste/micropython,Timmenem/micropython,tuc-osg/micropython,AriZuu/micropython,mhoffma/micropython,SHA2017-badge/micropython-esp32,swegener/micropython,swegener/micropython,pfalcon/micropython,chrisdearman/micropython,toolmacher/micropython,deshipu/micropython,blazewicz/micropython,blazewicz/micropython,henriknelson/micropython,matthewelse/micropython,cwyark/micropython,hosaka/micropython,tuc-osg/micropython,henriknelson/micropython,puuu/micropython,MrSurly/micropython-esp32,selste/micropython,hosaka/micropython,turbinenreiter/micropython,pramasoul/micropython,matthewelse/micropython,trezor/micropython,Timmenem/micropython,infinnovation/micropython,tobbad/micropython,tralamazza/micropython,alex-robbins/micropython,adafruit/circuitpython,selste/micropython,cwyark/micropython,swegener/micropython,hosaka/micropython,PappaPeppar/micropython,tralamazza/micropython,tralamazza/micropython,alex-march/micropython,puuu/micropython,adafruit/circuitpython,bvernoux/micropython,henriknelson/micropython,oopy/micropython,infinnovation/micropython,cwyark/micropython,infinnovation/micropython,ryannathans/micropython,pozetroninc/micropython,adafruit/micropython,ryannathans/micropython,henriknelson/micropython,tobbad/micropython,alex-march/micropython,TDAbboud/micropython,alex-march/micropython,oopy/micropython,alex-march/micropython,HenrikSolver/micropython,MrSurly/micropython,alex-robbins/micropython,blazewicz/micropython