Use Hugo's built in Site Config for copyright according to PR #199 (#240)

layouts/partials/site-footer.html

@@ -1,7 +1,7 @@
 <footer class="{{ .Site.Params.background_color_class | default "bg-black" }} bottom-0 w-100 pa3" role="contentinfo">
   <div class="flex justify-between">
   <a class="f4 fw4 hover-white no-underline white-70 dn dib-ns pv2 ph3" href="{{ .Site.BaseURL }}" >
-    &copy; {{ now.Format "2006" }} {{ .Site.Title }}
+    &copy; {{ with .Site.Copyright | default .Site.Title }} {{ . | safeHTML }} {{ now.Format "2006"}} {{ end }}
   </a>
     <div>{{ partial "social-follow.html" . }}</div>
   </div>