Add many more boards, and add more board placeholders

[dhalbert]

• Add all current boards
• Add placeholders for many more boards
• Move Teensy def to a better place
• Shorten checkbox menu in installation wizard.
• Fix nRF52840 typo in 32-bit driver section.
• Fix #19

[dhalbert]

@ladyada - User in https://forums.adafruit.com/viewtopic.php?f=59&t=156630 has verified this works for MONSTERM4SK on Windows 8.1, and I tested on Windows 7.