How to use XSLT extension points from a DITA-OT plugin

In these examples, the main page footer is modified by adding copyright information extracted from the DITA bookmap or by adding the output generation time. The first use-case uses an XSLT-Import extension point while the second uses an XSLT-Parameter extension point.

Note: This customization is available as a GitHub project at: https://github.com/oxygenxml/com.oxygenxml.webhelp.responsive.custom.footer.