v1.6

• Implement accessible dropdown menus. These menus should be navigable by keyboard and screen reader. Note: Top level navigation items toggle their child menu, which contains a link to the parent page. This is so there's no confusion what the top level link does on a keyboard (go to link destination vs open child menu).
• Use lightgallery wholly for default media viewer. Features include multiple file slides, rotation, zoom, video and pdf support.
• Include new theme settings for header heights, position, persistence.
• Update dependencies.