Determine how to set the site title tag dynamically from the settings collection

[brylie]

For SEO, the site title is currently configured from a variable set in /lib/_config/_config.js. Determine how to set the site SEO settings from the Settings collection, rather than hard-coding them into a file.

[brylie]

It turns out that we can set the site title when the template is rendered. That way we have access to the settings collection, etc. We can also set the page title from within layouts, but individual templates may be easier to maintain, since the layout title code may clash with individual templates.