v0.2 (Mechanics)

• v0.2 mechanical designs - laser-cut enclosure and gears
• This is the design seen in https://www.youtube.com/watch?v=bslkflVv-Hw and https://www.youtube.com/watch?v=1Df4Lg8UIck
• Fixes front window size/location, fixes enclosure tabs, adds flap backstop
• Known issues: Spool gear missing alignment hole; must be drilled manually (See #9)