Sticky Filters

Slight quality of life improvement for Dubolt. Now, when a user has enough vertical space on desktop, the filters stick to the top of the viewport when they scroll down far enough. Also, when a user has even more vertical space, a second player is rendered so they can get access to their playback controls without needing to scroll all the way to the bottom of the page.

Just pushed these changes out last night, let me know what you think about it.
See it live at https://dubolt.com