Prusa MK3 Filament Guide

I may or may not tweak this but for now I don't plan on making any changes.

I've never been happy with the filament guides I downloaded so I based this, loosely, off of JLTX's filament mount, https://www.thingiverse.com/thing:2727093 , as I really liked having a bearing with the guide. A couple of things made me not like it... First, it fit loosely in my Z brackets and second I could only feed filament from the side of the printer for this to work and I want to feed filament from behind t