add flow lines

README.md

@@ -157,6 +157,7 @@ Tools to create vector artwork from scratch or by conversion from other formats.
 - [plotting-maps](https://github.com/piebro/plotting-maps) - A simple web tool to create OpenStreetMap SVG maps for plotting.
 - [ThreadPlotter](https://github.com/LiciaHe/threadPlotter) - "A toolkit for the design and fabrication of delicate punch needle embroidery using X-Y plotters".
 - [PINTR](https://javier.xyz/pintr) - Plottable random line drawings from your images.
+- [Flow Lines](https://msurguy.github.io/flow-lines/) - A tool for generating flow line representations using SVG paths / polylines.
 
 ### Vector Utilities