Renamed _typography file to _base.
Updated to include _base. Removed styling.

What was the _typography.scss file was renamed to _base.scss so
that it was a more fitting name (since it included more than just
typography styling). Also, there were a couple of lines of styling
for the body class inside the primer.scss file that were moved to
the _base.scss file.
Fixed & automated color class naming style.
Made color variables into a Sass map.
Nested the styling within table element.
Added column offset classes.
Recompiled. Yet again.
Added basic styling for a navigation bar.