Use with

layouts/partials/footer.html

@@ -5,5 +5,7 @@
       <span aria-hidden="true"></span>
     </label>
   </div>
-  {{ .Site.Params.footer | markdownify }}
+  {{ with .Site.Params.footer }}
+    {{ . | markdownify }}
+  {{ end }}
 </footer>

layouts/partials/header.html

@@ -5,7 +5,9 @@
         <img src="{{ "images/logo.svg" | absURL }}" alt="">
       </a>
       <p class="library-desc">
-        {{ .Site.Params.description | markdownify }}
+        {{ with .Site.Params.description }}
+          {{ . | markdownify }}
+        {{ end }}
         </a>
       </p>
     </div>