Printer-friendlier Fidget Rocket

A printer-friendlier remix of [Eskimo_Pie's](https://www.thingiverse.com/Eskimo_Pie) wonderful fidget rocket.

## Technical Changes
* Made the ring connecting the outer engines taper off at the bottom, to only have one bridge thread on the lowest layer.

## Design Changes
* Removed the pre-set NASA text, so now you can add whatever you like in the slicer.
* Removed the

## Print settings
* Printer: BambuLab P1S
* Rafts: No
* Supports: No
* Resolution: 0.2mm and 0.4 mm work fine
* Infill: 10%
* Filament material: PLA, but should not matter too much