Non-HTML TOC markers break chapters without TOC

[mlange-42]

When using a TOC marker that is not HTML (as the default marker), chapters without the marker are broken.

Example: Use [[_TOC_]] as marker. It may be desired to have chapters without TOC, like an introduction or an appendix. These chapters will have several problems. What I observed so far:

• The page title (i.e. top-level heading like # Introduction) disappears
• Tables are broken (Marksdown-Tables as well as HTML tables).

This is what is expected:

But the result is this:

Chapters containing the marker render as expected.

[badboy]

Hey, sorry this issue got lost in my inbox. I'm looking into it.