RFR: JDK-8207213: The help-doc.html generated by the doclet is incomplete

[Jonathan Gibbons]

Please review a simple update to the help page generated by the standard 
doclet,
to add some text that was inadvertently omitted from the previous update.
JBS: https://bugs.openjdk.java.net/browse/JDK-8207213
Webrev: http://cr.openjdk.java.net/~jjg/8207213/webrev.00/index.html

-- Jon