add svg-crowbar to vector utilities

README.md

@@ -129,6 +129,7 @@ Tools to manipulate and optimize vector-based file formats.
 * [svgo](https://github.com/svg/svgo) – Node.js-based tool for optimizing SVG files.
 * [Polargraph Optimizer](https://github.com/ezheidtmann/polargraph-optimizer) - Optimize drawing plan for a polargraph.
 * [penkit-optimize](https://github.com/paulgb/penkit/tree/master/optimizer) – An SVG optimizer that uses a vehicle routing solver to minimize plot time.
+* [svg-crowbar](https://github.com/NYTimes/svg-crowbar) – Chrome-only bookmarklet for extracting SVG from an HTML document.
 
 ### Fonts