Redesigned home page
Please implement the following mockup from @mray, with the following adjustments:
- Keep the footer (and nav bar) as what is already live for the newest default layout stuff (ignore that part of the mockup, it's not what this issue is about)
- Remove period at end of "Crowdmatching for public goods" slogan above video.
- Put "Sign Up" and "learn more" right below the video (as well as keeping it below the text), but do not replicate the Mimi & Eunice characters in this location.
- Headings case consistency: change "Matching and Sustainability" to "Matching and sustainability".