Allow for string substitutions

Author: theute

src/main/jbake/content/docs/user/getting-started.adoc

@@ -18,7 +18,7 @@ and then unzip and start the server as shown below. You can find links to releas
 link:/downloads.html[Downloads] page.
 
 .Unzip and start the server
-[source,shell]
+[source,shell,subs="+attributes"]
 ----
 unzip hawkular-dist-{hawkular_released_version}.zip
 cd hawkular-{hawkular_released_version}