Look into switching how we initialize sliders

[andreekeberg]

It might be better to initialize it like this:

Slider.init('.header-slider', {
    loop: true,
    interval: 5000,
    duration: 1000,
    easing: 'cubic-bezier(.45,.08,.26,.99)',
})

Instead of setting a "type" in PHP and hard-coding these options in the slider.js file. This allows slider.js to be more general and configuration agnostic.