add heading
work on lesson 3
initial pass at potentiometers
add pot in breadboard image
edit pot section and start on transistors
transistor work
combine pot work with transistor work
start on NPN transistors
add npn transistor symbol
Merge branch 'lessonthree' of github.com:wileycousins-edu/intro_to_circuits into lessonthree
npn work continues
reorganize material structure
update main readme to reflect new structure