Update README.adoc

Author: abrokenjester

README.adoc

@@ -7,7 +7,8 @@ http://www.rdf4j.org/[Eclipse RDF4J] (formerly known as Sesame) is a powerful Ja
 Spotted a typo? Have something else to improve or fix in the documentation? Great! We love to receive your fixes and improvements! Before you start editing, please make sure that:
 
 1. you have signed the Eclipse Contributor License Agreement (CLA);
-2. you know how to 'sign off' every commit do.
+2. you know how to 'sign off' every commit do;
+3. you know what http://asciidoctor.org/docs/asciidoc-syntax-quick-reference/[AsciiDoc syntax] is. 
 
 You can find more details about this in the https://github.com/eclipse/rdf4j-doc/blob/master/.github/CONTRIBUTING.md[Contributor guidelines for the RDF4J Documentation].