Include example URLs in documentation

[nichtich]

The DESCRIPTION should also include example URLs, as given in SYNOPSIS:

• HTTP GET/POST format parameter
  e.g. format is set to xml for http://example.org/foo?format=xml if format xml has been defined.
• URL path extension
  e.g. format is set to xml for http://example.org/foo.xml if format xml has been defined.
• HTTP Accept Header
  e.g. format is set to xml if format xml has been defined with content type application/xml for Accept header value "application/xml"