When there is a file starting with de, the configuration defaulted the
lang value to de. This way, the multilingual implementation breaks. This
is fixed by properly specifying the path with a slash in the end.

This does not implement multilanguage support for the whole website, but
only for the content of specific pages.

This is achieved by reducing the size of the h1 heading from 4 to 3rem
and reducing the bottom padding from 3 to 2rem.