resolves #1315 reword the explanation for the line-height-length key [skip ci]
resolves #1315 reword the explanation for the line-height-length key [skip ci]

dsisnero/asciidoctor-pdf,mojavelinux/asciidoctor-pdf,Hextremist/asciidoctor-pdf,Hextremist/asciidoctor-pdf,asciidoctor/asciidoctor-pdf,dsisnero/asciidoctor-pdf,asciidoctor/asciidoctor-pdf,mojavelinux/asciidoctor-pdf