Add the siteName param so site name can optionaly be set to visually-hidden.

layouts/_default/baseof.html

@@ -21,7 +21,7 @@
 <img src="{{ with $.Param "logopath" }}{{ . | relURL }}{{ else }}{{ "images/logo.png" | relURL }}{{ end }}"{{ with $.Param "logowidth" }} width="{{ . }}"{{ end }}{{ with $.Param "logoheight" }} height="{{ . }}"{{ end }} alt="Home" class="header__logo-image">
 </a>
 {{ end -}}
-<h1 class="header__site-name">
+<h1 class="header__site-name{{ if not ($.Param "sitename" | default true) }} visually-hidden{{ end }}">
 <a href="{{ site.Home.RelPermalink }}" title="Home" class="header__site-link" rel="home"><span>{{ site.Title }}</span></a>
 </h1>
 <div class="region header__region">