add usage reference to Converter#convert_with_options method
add usage reference to Converter#convert_with_options method

cuit-zhaxin/asciidoctor,anthonny/asciidoctor,neontapir/asciidoctor,asciidocfx/asciidoctor,yukisan/asciidoctor,glamouracademy/asciidoctor,mjang/mj-asciidoc,glamouracademy/asciidoctor,mjang/mj-asciidoc,benignbala/asciidoctor,gjtorikian/asciidoctor,pepijnve/asciidoctor,cuit-zhaxin/asciidoctor,pepijnve/asciidoctor,asciidocfx/asciidoctor,anthonny/asciidoctor,benignbala/asciidoctor,yukisan/asciidoctor,neontapir/asciidoctor,gjtorikian/asciidoctor