Add Webpage for fourth datathon

[SamFritz]

Add in structure for fourth datathon, pulling on outline from previous datathon pages. Content to be added:

• [x] Intro image (save the date)
• [x] Information about the datathon
• [x] Organizers
• [x] Sponsor logos
• [x] Important Dates
• [x] Submission details
• [x] Travel grants

PR to be put in after Dave the date information has been released

Edits completed on ny-datathon branch

[SamFritz]

Issue closed and addressed by PR #136: Add NY datathon webpage