v0.3.0

This release focuses on performance improvements:

• The widget only performs draws if it has views that are visible in the browser. So if an animated widget scrolls out of the viewport, it won't consume CPU.
• The widget now uses JPEG encoding for the images, which is much faster to encode, and faster to send over (smaller payload). There is also a new quality trait to control the quality. At the end of an interaction the widget always sends a lossless PNG so the static image always looks perfect.

Further:

• Improvements to docs.
• Improvements to contributor guide.