added assets for displaying video on fable case study page.
fable module is loaded when JS identifies that the current page is the fable case study page.
added CSS changes to accomodate fable case study video.
improved blending of background video on the fable legends case study.
moved fable JS into  directory.
build script now compiles fable case study JS into it's own module that will only be loaded when the page is the fable case study page.