Dear Stack Overflow community,
I'm hosting a blog on Github Pages which is running on Jekyll. Canonicalization works fine on the index page (usabilityreport.de -> www.usabilityreport.de) whereas it doesn't on subpages. usabilityreport.de/user-experience should lead to this page but instead it results in a generic 404 page.
GitHub does not allow .htaccess files so I can't use RewriteEngine On. My research has only lead me to a canonicalization tag in the which has no effect.
<link rel="canonical" href="{{ site.url }}{{ page.url | replace:'index.html',''}}">
The complete code is available on GitHub.