On mobile devices with browser chrome (UI) that recedes on scroll,
'vh' includes the height covered by chrome, which 'dvh' does not.
By using 'dvh' the footer is immediately visible on the homepage
without scrollbar on mobile devices.
BTW: Rename the manufacturer-specific name ``ion-icon`` of the icon set in
SerXNG to ``sxng-icon-set`` --> The icon set can be assembled together as
desired in the FE and should therefore not have a manufacturer-specific name in
the style and template definitions.
Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>
