Support for choosing line break position in page-title

[SilverFox70]

Aesthetically this has some intersection with #308 and also relates to Brand Center #443. The desire is to be able to finesse where a line break occurs in the page-title as it appears in the PageHeader. We did a brief exploration of achieving this:

<h1 id="page-title" className={text}>
  <div dangerouslySetInnerHTML={{ __html: frontmatter.title || null }}/>
</h1>

[vpicone]

@SilverFox70 This approach wouldn't work for any other places in the site that use title: search, custom navigation components, the HTML title header. I have an alternative approach that I'm pushing now.