add a cool tool for plotter text (#60)

* add a cool tool for plotter text

* Update README.md

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Co-authored-by: Brian Boucheron <brian@boucheron.org>

README.md

@@ -171,6 +171,7 @@ Single-line vector fonts or "engraving fonts".
 - [hershey-fonts](https://github.com/kamalmostafa/hershey-fonts) - C library and original font data for the Hershey fonts.
 - [svg-fonts](https://gitlab.com/oskay/svg-fonts) - Single-line fonts in an SVG format, mainly for use with the [Hershey Text](https://gitlab.com/oskay/hershey-text) Inkscape plugin.
 - [CNC Text Tool](https://msurguy.github.io/cnc-text-tool/) - Browser-based Hershey Text tool with export to SVG.
+- [hf2gcode](https://github.com/Andy1978/hf2gcode) - Generates G-code from text with a Hershey font.
 
 ## Inspiration, Instruction, and Research