Add SVGPathData.from{shape} methods

[nfroidure]

Those methods are implemented here but I think would better sit in this module.

https://github.com/nfroidure/svgicons2svgfont/blob/master/src/svgshapes2svgpath.js

By example:

SVGPathData.fromRect(0, 0, 40, 30)

[NaridaL]

Do you just want to copy those methods? The fromRect syntax you're proposing isn't entirely compatible with reading creating paths from svg shape elements. fromRect({x: 0, y: 0, width: 40, height: 30}) would work for both.

Also why is the circleToPath method using 4 C commands instead of As ?!

[nfroidure]

Tbh I dropped it there without actually thinking on the implementation, you're the best suitable to choose it.

For the circleToPath method, it was just quick and dirty design, was need to SVG at that moment ;).

[NaridaL]

Thinking about it, I'm not entirely sure this makes sense. The functions in svgicons2svgfont are pretty focused on converting from svg ellipse etc tag attributes (including parsing numbers), as such doesn't necessarily fit here, which is exclusively focused on the path part of SVG.