Reorganization/Cleanup

- Split index.html into 2 files (wrapped & full-width)
- Add basic text to style & basic css styling for paragraphs, lists, headings, etc.
- Add comments for gradient mixins
- Add styles for different input types
Responsive Menu Templates

- Add css & js for different menu styles
- Add supporting html to starter index files
- Add wp_nav_menu call with necessary options to header file