:title [second hole and screw])
(subsection
:title [third and fourth hole and screw]))
+ (section
+ :title [breadboard])
(section
:title [battery packs]
(subsection
(section
:title [serial]
(subsection
- :title [arduino software on computer])
+ :title [software on computer]
+ (subsection
+ :title [arduino])
+ (subsection
+ :title [fritzing]))
(subsection
:title [attach arduino and computer via cable])
(subsection