tweaks
new tutorial
typos
Tutorial on software PWM
Update PWM.md

Typo
MacOS connection info
Better LED tutorial
Merge branch 'master' of github.com:espruino/EspruinoDocs
Merge pull request #23 from siu/patch-1

Update PWM.md
Merge pull request #22 from kimbauters/patch-1

Tutorial on software PWM
PWM tutorial
update based on feedback about some LED strings