In footer, derive copyright from author name (#374)

Hugo 0.120 changed the name author is specified:
gohugoio/hugo@d4016dd

Author: stefanv

doc/config.yaml

@@ -10,6 +10,8 @@ markup:
     noClasses: false
 
 params:
+  author:
+    name: "Scientific Python team"
   description: "Documentation & template site for the Scientific Python Hugo Theme."
   images:
     - /images/logo.svg

layouts/partials/footer.html

@@ -1,4 +1,5 @@
-{{- $title          := .Site.Params.title }}
+{{- $title       := .Site.Title }}
+{{- $author      := .Site.Params.author.name }}
 {{- $footer      := .Site.Params.footer }}
 {{- $logo        := index $footer "logo" }}
 {{- $quickLinks  := index $footer "quicklinks" }}
@@ -43,7 +44,7 @@
               {{- end }}
             </div>
           </nav>
-          <div class="copyright">&copy; {{ now.Year}} {{ $title }}. All rights reserved.</div>
+          <div class="copyright">&copy; {{ now.Year}} {{ $author }}. All rights reserved.</div>
         </div>
     </div>
   </div>