While updating the docs, discovered that the following link is broken:

https://xmlns.opennms.org/xsd/config/model-import

Discussion on engineering channel indicates xmlns is broken. Further discussion determined we "should be publishing these in an entirely different way, and then fix up the XSD locations".

Docs updated to go to this link (https://raw.githubusercontent.com/OpenNMS/opennms/develop/opennms-provision/opennms-provision-persistence/src/main/resources/xsds/model-import.xsd) until issue is fixed.