Split Filament Sensor Cover for Bear Extruder

This is a split filament sensor cover for the Bear Extruder. It will allow you to clear clogs and jams easier by sliding half of the filament sensor cover out of the way to access the PTFE tube, rather than having to take the whole filament sensor cover off. I also added two knobs to the top of it that help you slide it and take the sensor cover off.

This is for [bear extruder](https://www.thingiverse.com/thing:3226689) by Greg Saun. It's a much better extruder than stock Prusa MK3 extruder.