Eggbot Coordinate Demo Using Hershey Text

The original was great to have, but I made these tweaks:

- The labels have been replaced with larger text generated using the Hershey Text extension. These labels should be now be super-legible, even on objects as small as ping pong balls. :D

- After looking at Inkscape's y-axis orientation and the eggbot pen-motor orientations, the y-position labels have been vertically swapped.

- The paths are now organized into layers named "Grid Lines", "Direction Markers", and "Labels". :)

Futur