Restrict course preview to published courses only

[weberandreaseu]

Course collection should be restricted to published courses only. Current workaround filters after slicing:

website-theme/clean-blog/templates/modular/course-section.html.twig

Line 7 in fae1c42

{% for page in page.find('/courses').children.order('date', 'desc').slice(0, 5) %}