Baker rendering modes

Since Baker 3.0 we are supporting two rendering modes:

1. screenshots: pages are screenshotted the first time they are visualized and, from that moment on, Baker will display screenshots for a brief moment before showing the loaded HTML. Thanks to PugPig for the idea.
2. three-cards: following and previous pages are fully loaded while the reader is on a specific page, so they are already loaded when the users moves one page forward or backward.

For more info, see -baker-rendering among the extension parameters.