Packed Discs for "Automatic Sortable Connect 4 - sysshad"

I used OpenSCAD to (derive the dimensions and) pack the discs close enough together in order to barely fit them onto my build plate at the same time as the `SliderBack_7x_v34` piece. The `SliderBack_7x_v34` is not modified; it is the original .stl provided by **@sysshad**. But I just included it to make it clear that the packed discs are meant to be printed at the same time as the `SliderBack_7x_v34`s.

The reason I wanted to print them all at the same time is because I have color changing filament, and the more on the build plate at once, the faster the colors change. So doing this allows my discs to look very cool.

Remixed from https://www.thingiverse.com/thing:3542969.
(He selected the No Derivatives license, but I got permission from him to post a remix.)