Sometimes people try to make a heading, and because subheading 2-4 all look like just bolded text in Vector (and subheading 1 just looks like slightly-larger bold text), they bold it rather than using heading markup. This visually works, but means these "headings" don't show up in the table of contents. (And the accessibility isn't great.)
We should detect paragraphs that are completely covered by a bold annotation, and offer to convert them to a heading.
The complexity of this, compared to T412878, is that it's not necessarily obvious which heading level to offer. Possible options include:
- The same as the previous heading
- One below the previous heading
- Either of the former, but never higher than "sub-heading 1" (because it's the first one that looks almost-identical to bolded text)
(And this all only holds if the person is editing in Vector. Other skins have different styling for headings.)