Allow horizontal scrolling in absolute layout mode

This is a quick fix to make elements that are currently unreachable,
reachable. The problem exists thanks to the `min-width: 1100px` set
on the <html>-element. A better solution would be to remove this
property and take care to make individual page components (especially
navigation) work responsively.

See 00506ca9.

Signed-off-by: Alex Coles <alex@alexbcoles.com>
Merge pull request #1915 from opf/fix/horizontal-page-scrolling

Allow horizontal page scrolling in absolute layout mode