Add social media social share preview code to project pages

[jonfroehlich]

We don't currently render anything special for social media shares: https://socialsharepreview.com/?url=https://makeabilitylab.cs.washington.edu/.

We should fix this. On landing page, should show intriguing header image. On individual project pages, show project header

[jonfroehlich]

The social media preview looks like this:

But we should really customize it on project pages

[jonfroehlich]

We've added this for the main landing page but not project pages

[jonfroehlich]

Actually, upon further investigation, it looks like we have done this for project pages: