Add 'no schematic' image for 1.a.i.2.
Fix 1.a.i.3.
Fix power supply 1.a.i.4.
Fix voltage divider Frizzing.
Fix 1.a.i.5.
Fix 1.a.i.6.
Fix 1.8.i.7.
Add reference links to 1.a.i.8.
Copy edits throughout 1A.  Basic 1.A.i overview.