Clean up CSS

- Add vim folds to make organized sections
- Rename a lot of classes from post- to page-
- Generalize series CSS classes better
- Clean up navbar div structure
- Remove langpicker and most of multilingual support
- many other minor tweaks

layouts/_default/summary.html

@@ -1,10 +1,10 @@
-<h2 class="post-title">
+<h2 class="page-title">
     {{ with .Parent.Params.icon }}{{ partial "icon.html" . }}{{ end }}
-    <a href="{{ .Permalink }}">{{ .Title | markdownify }}</a>
+    <a class="heading-link" href="{{ .Permalink }}">{{ .Title | markdownify }}</a>
     {{ if .Draft }}{{ partial "icon.html" "write" }}{{ end }}
 </h2>
 
-{{ partial "post-metadata/short.html" . }}
+{{ partial "page-metadata/post-short.html" . }}
 
 {{ with .Resources.GetMatch "feature" }}
     <div class="post-media">
@@ -12,7 +12,7 @@
     </div>
 {{ end }}
 
-<div class="post-description">
+<div class="page-description">
     {{ partial "description-or-summary.html" . }}
 </div>