* Add a license param in the config used in footer
Also adds initial EN and NL i18n statements referring to the license.
* Add Michiel to CONTRIBUTOR
* Add example text for i18n of `licensed_under`
* Add safeHTML filter to license value in the footer
Also updates the example config in the exampleSite config.toml to link
to Creative Commons.
* Fix separator dot in footer within License ifdef
