markdownlint/doc-build/md023.md

This rule is triggered when a heading is indented by one or more spaces:

Some text

  # Indented heading

To fix this, ensure that all headings start at the beginning of the line:

Some text

# Heading

Note that scenarios like block quotes "indent" the start of the line, so the following is also correct:

> # Heading in Block Quote

Rationale: Headings that don't start at the beginning of the line will not be parsed as headings, and will instead appear as regular text.