Parametric filament ruler (** Use the Updated Version)

A remix of the ruler from https://www.thingiverse.com/thing:3886663
**A better V2 at https://www.thingiverse.com/thing:5998096**

I accumulated loads of different filament brands and roll sizes with no real way of knowing how much was left on each roll.

I took the design by hsiehty and remixed it to
* Label the notches rather than have square and circular holes
* have as many, within reason, reporting notches as you want
* allow you to specify reporting at a %age or m left (label is always in m)
* allow you to add an unlabelled 10m notch

Use the Customizer to make one for yourself if you don't have Openscad