docs/uctypes: Improve documentation.
docs/uctypes: Improve documentation.

Seealso and Limitations sectiosn added, better formatting and grammar.

pfalcon/micropython,emfcamp/micropython,pozetroninc/micropython,henriknelson/micropython,chrisdearman/micropython,tuc-osg/micropython,infinnovation/micropython,kerneltask/micropython,dinau/micropython,mhoffma/micropython,pfalcon/micropython,MrSurly/micropython,PappaPeppar/micropython,swegener/micropython,AriZuu/micropython,puuu/micropython,HenrikSolver/micropython,infinnovation/micropython,blazewicz/micropython,ryannathans/micropython,SHA2017-badge/micropython-esp32,adafruit/circuitpython,PappaPeppar/micropython,redbear/micropython,dxxb/micropython,puuu/micropython,ryannathans/micropython,hiway/micropython,alex-robbins/micropython,cwyark/micropython,chrisdearman/micropython,swegener/micropython,toolmacher/micropython,pfalcon/micropython,PappaPeppar/micropython,torwag/micropython,deshipu/micropython,hosaka/micropython,MrSurly/micropython,dmazzella/micropython,tralamazza/micropython,pfalcon/micropython,pramasoul/micropython,toolmacher/micropython,jmarcelino/pycom-micropython,HenrikSolver/micropython,cwyark/micropython,micropython/micropython-esp32,torwag/micropython,AriZuu/micropython,lowRISC/micropython,hosaka/micropython,MrSurly/micropython,HenrikSolver/micropython,pramasoul/micropython,hosaka/micropython,oopy/micropython,puuu/micropython,SHA2017-badge/micropython-esp32,tobbad/micropython,lowRISC/micropython,alex-robbins/micropython,alex-march/micropython,jmarcelino/pycom-micropython,adafruit/circuitpython,torwag/micropython,Peetz0r/micropython-esp32,kerneltask/micropython,pfalcon/micropython,tobbad/micropython,cwyark/micropython,AriZuu/micropython,emfcamp/micropython,dxxb/micropython,micropython/micropython-esp32,adafruit/micropython,deshipu/micropython,MrSurly/micropython-esp32,bvernoux/micropython,adafruit/micropython,adafruit/circuitpython,trezor/micropython,AriZuu/micropython,blazewicz/micropython,puuu/micropython,micropython/micropython-esp32,blazewicz/micropython,alex-march/micropython,oopy/micropython,dmazzella/micropython,blazewicz/micropython,trezor/micropython,matthewelse/micropython,adafruit/circuitpython,cwyark/micropython,selste/micropython,alex-march/micropython,alex-robbins/micropython,kerneltask/micropython,dxxb/micropython,swegener/micropython,MrSurly/micropython,chrisdearman/micropython,infinnovation/micropython,MrSurly/micropython-esp32,Timmenem/micropython,MrSurly/micropython-esp32,Peetz0r/micropython-esp32,pramasoul/micropython,Timmenem/micropython,Peetz0r/micropython-esp32,chrisdearman/micropython,kerneltask/micropython,henriknelson/micropython,torwag/micropython,TDAbboud/micropython,redbear/micropython,tuc-osg/micropython,SHA2017-badge/micropython-esp32,adafruit/circuitpython,ganshun666/micropython,dinau/micropython,emfcamp/micropython,trezor/micropython,infinnovation/micropython,selste/micropython,pozetroninc/micropython,ryannathans/micropython,deshipu/micropython,hiway/micropython,tralamazza/micropython,oopy/micropython,pozetroninc/micropython,jmarcelino/pycom-micropython,pramasoul/micropython,turbinenreiter/micropython,Timmenem/micropython,hiway/micropython,dmazzella/micropython,blazewicz/micropython,swegener/micropython,ganshun666/micropython,MrSurly/micropython-esp32,infinnovation/micropython,pozetroninc/micropython,dinau/micropython,adafruit/circuitpython,AriZuu/micropython,TDAbboud/micropython,tuc-osg/micropython,ryannathans/micropython,adafruit/micropython,PappaPeppar/micropython,tuc-osg/micropython,turbinenreiter/micropython,tobbad/micropython,jmarcelino/pycom-micropython,lowRISC/micropython,matthewelse/micropython,mhoffma/micropython,redbear/micropython,HenrikSolver/micropython,redbear/micropython,PappaPeppar/micropython,toolmacher/micropython,mhoffma/micropython,SHA2017-badge/micropython-esp32,kerneltask/micropython,mhoffma/micropython,lowRISC/micropython,micropython/micropython-esp32,matthewelse/micropython,alex-march/micropython,ganshun666/micropython,turbinenreiter/micropython,emfcamp/micropython,henriknelson/micropython,turbinenreiter/micropython,matthewelse/micropython,hosaka/micropython,lowRISC/micropython,alex-robbins/micropython,hiway/micropython,dinau/micropython,matthewelse/micropython,bvernoux/micropython,bvernoux/micropython,pozetroninc/micropython,Timmenem/micropython,trezor/micropython,Peetz0r/micropython-esp32,Peetz0r/micropython-esp32,swegener/micropython,ganshun666/micropython,redbear/micropython,SHA2017-badge/micropython-esp32,dxxb/micropython,TDAbboud/micropython,ganshun666/micropython,deshipu/micropython,turbinenreiter/micropython,oopy/micropython,toolmacher/micropython,MrSurly/micropython-esp32,chrisdearman/micropython,puuu/micropython,cwyark/micropython,tobbad/micropython,hiway/micropython,deshipu/micropython,henriknelson/micropython,dinau/micropython,matthewelse/micropython,trezor/micropython,bvernoux/micropython,bvernoux/micropython,tralamazza/micropython,ryannathans/micropython,tobbad/micropython,selste/micropython,micropython/micropython-esp32,alex-march/micropython,MrSurly/micropython,dxxb/micropython,selste/micropython,selste/micropython,tralamazza/micropython,dmazzella/micropython,HenrikSolver/micropython,toolmacher/micropython,adafruit/micropython,mhoffma/micropython,emfcamp/micropython,pramasoul/micropython,TDAbboud/micropython,jmarcelino/pycom-micropython,torwag/micropython,Timmenem/micropython,hosaka/micropython,tuc-osg/micropython,oopy/micropython,henriknelson/micropython,alex-robbins/micropython,adafruit/micropython,TDAbboud/micropython