titleTemplate should take a function

[homerjam]

Ideally I'd like to be able to determine whether or not to place dividers in the title (eg. pipes or hyphens).

titleTemplate: (titleChunk) => {
  // If undefined or blank then we don't need the hyphen
  return titleChunk ? `${titleChunk} - Site Title` : 'Site Title';
}

[atinux]

Hi @homerjam

This should be backward compatible as well, any PR is welcome :)