Fixed footer social buttons on desktop and mobile, refined footer navigation text to be consistent with the theme, footer theme matches new documentation theme
Fixed footer social buttons on desktop and mobile, refined footer navigation text to be consistent with the theme, footer theme matches new documentation theme

ellisonbg/jupyter.github.io,ellisonbg/jupyter.github.io,ellisonbg/jupyter.github.io,ellisonbg/jupyter.github.io,ellisonbg/jupyter.github.io