Set site wide design and styling.

- Add gridism CSS component for responsive design.
- Add section in readme with open source usage in repository.
- Include Open Sans from Google Fonts.
- Update the current design to use gridism.
Design front page with simple save the date look.

- Add cover image with picture of us.
- Include Google Font: Great Vibes in layout view.
- Update index view to show the Save the Date look.
Add Google Analytics for the site.