Nanosaur

General improvement on the nanosaur code

Fixes

- Default ball bearings F686ZZ

Fixes

- Fix `base_front.stl` error

This version enlarge the dock area for different type of power banks, now the maximum size is: **66 mm x 94 mm x 24 mm or 2.5' x 3.7' x 0.9'**

STL changed:

- `base_rear.stl`
- `cover.stl`
- `pb_holder.stl`

First nanosaur release