Shortcodes

This is a parser for the shortcode spec as explained in the Hugo docs and used in Hugo and Nikola. Approximately.

I am implementing this for Nicolino.

It probably won't be 100% identical, but I'll try to make it as close as practical.

• Implemented in Ragel + C for performance
• Allocates no memory, because all strings are references to pieces of input.

What works:

• Detect shortcodes with names
• Standalone and matched shortcodes
• Capture data between tags in matched shortcodes
• Capture arguments with and without names
• Capture values with and without quotes (with details, see TODO above)