copy in texastribune's reset

to prove I haven't gone insane, also stub out it's eventual replacement
at the same time.
move box sizing to normalize
group color settings together
move collectstatic before sass instead of runserver
add basic typography example to the homepage
fix grid example cell styling was lost
delete broken clearfix mixin
disable legacy support for smaller css
restrict debug grid css to .example space
add emphasis to .grid too

note: prefer outline over border because borders affect the flow of the
document.
add nested grid example

overhaul background colors to illustrate nesting better.
we can use rgba because we don't care about IE8 for the doc site.
move typography into an include, dump it down a well
add relative typography sizing demo
exaggerate border-radius to demo how it scales