Add initial support for item shortcode.
Adds general items shortcode. Adds collection shortcodes. Minor fixes.
Fixed featured_items to use random param.
Fixed collection shortcodes to work with partial view.
Small fixes
Added file shortcode
Fixed file shortcode to not break site if file ID is not provided.
Fixes file shortcode to allow for true false options.
Actually fixes file shortcode to allow for true false options.
Small code standards fixes for shortcodes.