toPlainText
Converts processed InlineContent to its plain text representation. For example, the Markdown input foo **bar baz** has foo bar baz as its plain text.
Note: this is a quick and efficient implementation, practical for the use cases inside the core compiler (e.g., stripping away formatting from image labels). For a full-fledged plain text rendering, see the quarkdown-plaintext module instead.
Return
plain text of the inline content
Parameters
renderer
optional renderer to use to render critical content and text symbols