Massive cleanup

- Simpler main nav on all pages
- Back to purple masthead on homepage instead of dark graphite
- Active link styles on the main nav
- Cleaned up sidebar nav
- New docs layout name
- Homepage copy edits
- Updated bright purple docs color

Gruntfile.js

@@ -362,6 +362,10 @@ module.exports = function (grunt) {
       sass: {
         files: 'scss/**/*.scss',
         tasks: ['dist-css', 'docs']
+      },
+      docs: {
+        files: 'docs/assets/scss/**/*.scss',
+        tasks: ['dist-css', 'docs']
       }
     },