Add caching to some partials that don't change much

layouts/partials/top.html

@@ -0,0 +1,10 @@
+<h2 class="header">
+    <a href="{{ "/" | relURL }}">{{ .Site.Title | markdownify }}</a>
+</h2>
+
+<nav id="navbar">
+    <a class="navbar-item" href="{{ "/" | relURL }}">Home</a>
+    {{ range .Site.Menus.main }}
+    <a class="navbar-item" href="{{ .URL }}">{{ .Name }}</a>
+    {{ end }}
+</nav>