Caliper Holders

This is a caliper holder designed to fit on the Ender 3 Pro top bar. It is a remix of [this one](https://www.thingiverse.com/thing:3318538) which was too thin to fit my calipers. I also made the T-nut fitting a little bit larger so it would fit a little more snuggly.

Keep an eye out for collisions in very tall prints since the calipers do hang down a little into the print area.