Search title shouldn't be required anymore

[TylerFisher]

We should just fall back to headline if it's blank, like we do for FB/Twitter

[chelsea-tnc]

It looks like there was a pull request, but it didn't get merged. Was there something blocking?

[TylerFisher]

I think this is one of those things that got written before the Vercel platforms migration, so I couldn't merge it after we made the migration. The idea is that the frontend (next-tinynewsdemo) code is written to fallback to the headline for search titles if people don't provide a search title. However, in the Google Apps Script form, our form validation requires that a search title is provided. We should remove that validation from the form here.