disk launcher 2.0

This is a remix of [bongoboy23's](https://www.thingiverse.com/bongoboy23/about) [disk shooter](https://www.thingiverse.com/thing:7643).

The main improvements are less filament used, better tolerances, a finger ring to pull the slide back, there are two versions, one is integral to the slide, the other is a add on for the original slide, and i also improved the connection between the handle and barrel. You can currently use the scad file for the finger ring slide (need a better name for that), more will be included at a later date such as the handle, ammo holder, and ammo discs.

If i feel like it, i may make a mechanism that lets you cock it without actually firing it. I may also make a scad file for the finger ring and slider with built in finger ring for sizing (done!). and if i can figure out how, i may make a scad file for customizing the disks with a image, don't know if that's something i can do yet.

You can make requests, i'm open to all and any input, and feel free to r