HTML transformations

You may want to make universal changes to the HTML of your books just before they are output. These are called transformations.

The template already includes some transformations:

Transformations are currently supported for epub and PDF outputs only.

To add a transformation for epub output, add a file containing a single function file to _tools/gulp/transformations/epub. You would do the same for PDF by adding a function file to _tools/gulp/transformations/pdf.

For guidance on the structure of the function, follow the existing files. For syntax, these functions use Cheerio.