Plugin always tries to use auto-generated IDs #184
Description
This plugin seems to presume the existence of Kramdown auto-generated IDs. These do not exist when Kramdown auto_ids is set to false, or when simply using raw HTML, yet the plugin links to them regardless.
If a custom ID is defined via Kramdown syntax, the plugin will recognize it. Otherwise, it will link to every header despite them having no ID.
With raw HTML, the plugin does not respect any IDs specified, nor the lack of an ID, and just uses an auto-generated name for all of them.
Ideally, it would always use the real IDs for the headers, and if one does not exist, not show the header in the TOC.