[PATCH] Documentation: fix header markup

Asciidoctor is stricter than AsciiDoc when deciding if underlining is a section title or the start of preformatted text. Make the length of the underlining match the text to ensure that it renders correctly in all implementations. Signed-off-by: Xue Fuqiao --- Currently,

Re: [PATCH] Documentation: fix header markup

Xue Fuqiao writes: > Asciidoctor is stricter than AsciiDoc when deciding if underlining > is a section title or the start of preformatted text. Make the > length of the underlining match the text to ensure that it renders > correctly in all implementations. > >