Removed outerContainer mixin

Because it was constraining entire page to 68rem
Removal of unnecessary & redundant code

Mostly redundant + unnecessary size mixins
Minor formatting and positioning changes
Possible background images

Unused at this point. Still figuring out how to make a responsive
background image work in Wordpress.
Formatting for the hero image

When I figure out how to actually make it work.
Forgotten opening tag added
Added ACF (advanced custom fields) plugin