EML documentation incorrect for licensed field

[mbjones]

@LennertSchepers reported a documentation mistake for licensed in #282:

Hi, I believe that the example in the xsd (and interactive schema) shows <license> instead of <licensed>. See

eml/xsd/eml-resource.xsd

Lines 388 to 392 in fe77f8f

	<license>
	<licenseName>Apache License 2.0</licenseName>
	<url>https://spdx.org/licenses/Apache-2.0.html</url>
	<identifier>Apache-2.0</identifier>
	</license>

Fix by updating the schema docs, and regenerate the documentation site.