Honor the Hugo Goldmark Extras extension when rendering TOC entries

[jmooring]

Low priority.

Site configuration

[markup.goldmark.extensions]
strikethrough = false

[markup.goldmark.extensions.extras.delete]
enable = true

[markup.goldmark.extensions.extras.insert]
enable = true

[markup.goldmark.extensions.extras.mark]
enable = true

[markup.goldmark.extensions.extras.subscript]
enable = true

[markup.goldmark.extensions.extras.superscript]
enable = true

Markdown

## Hydrogen (H) is the 1^st^ element in the periodic table

## Water (H~2~O) is a liquid

## Water (H~2~O) is a ~~liquid~~ ++compound++

## Water (H~2~O) is an ==organic compound==

Actual TOC

Desired TOC