layouts: Rename list to section and single to page

This makes them more specific. For example, section.html can't
accidentally be a fallback for taxonomy.html, and page.html can't for
term.html.

Fixes #88

layouts/section.html

@@ -0,0 +1,25 @@
+{{ define "main" }}
+    <h1>
+        {{ with .Params.icon }}{{ partial "icon.html" . }}{{ end }}
+        {{ .Title | markdownify }}
+        {{ partial "rss-link.html" . }}
+    </h1>
+
+    {{ with .Content }}
+        {{ . }}
+    {{ end }}
+
+    <div class="list-page-container">
+        {{ with .Sections }}
+            <div class="sections">
+                {{ range . }}
+                    {{ .Render "summary" }}
+                {{ end }}
+            </div>
+        {{ end }}
+
+        {{ partial "page-list.html" .Paginator.Pages }}
+    </div>
+
+    {{ partial "pagination.html" . }}
+{{ end }}