Remove heavy query on "head" partial

[mattstratton]

currently, partials/head.html is doing a data lookup to figure out the <title> element for each page. It does this to set the title according to the city, etc

It's a little heavy, and we should be able to just get it from the frontmatter (part of the issue is that the "Title" element in frontmatter is used as the heading on the actual page, and it probably shouldn't match what we want in the title element

I'm not sure this is an essential fix, but should be looked into.