You can optionally define SITE_LICENSE variable in Pelican configuration. It will appear in the footer of the site.
For example,
SITE_LICENSE = """Content licensed under <a rel="license nofollow noopener noreferrer"
href="http://creativecommons.org/licenses/by/4.0/" target="_blank">
Creative Commons Attribution 4.0 International License</a>."""
It appears as
