The `link` parameter is used to control whether the scaled down image links
to the full size version. By default it does; set "link=somepage" to link
-to another page instead, or "link=no" to disable the link.
+to another page instead, or "link=no" to disable the link, or
+"link=http://url" to link to a given url.
You can also set default values that will be applied to all later images on
the page, unless overridden. Useful when including many images on a page.