feat: add span with class 'gdoc-brand__title' around site title (#168)

* Add CSS span to site title to allow for something I do on my site (where I use a larger logo and hide title except in narrow views)

* Update layouts/partials/site-header.html

Co-authored-by: Robert Kaussow <xoxys@rknet.org>

Co-authored-by: Robert Kaussow <xoxys@rknet.org>

layouts/partials/site-header.html

@@ -9,7 +9,7 @@
         <a class="gdoc-header__link" href="{{ .Root.Site.BaseURL }}">
             <span class="gdoc-brand flex align-center">
                 <img class="gdoc-brand__img" src="{{ (default "brand.svg" .Root.Site.Params.GeekdocLogo) | relURL }}" alt="">
-                {{ .Root.Site.Title }}
+                <span class="gdoc-brand__title">{{ .Root.Site.Title }}</span>
             </span>
         </a>
         <span id="gdoc-dark-mode">