Use title case for 'posts' translation (#338)

layouts/posts/list.html

@@ -1,9 +1,9 @@
 {{ define "title" }}
-  {{ i18n (lower .Title) | default .Title }} · {{ .Site.Title }}
+  {{ title (i18n (lower .Title)) | default .Title }} · {{ .Site.Title }}
 {{ end }}
 {{ define "content" }}
   <section class="container list">
-    <h1 class="title"> {{ i18n (lower .Title) | default .Title }} </h1>
+    <h1 class="title"> {{ title (i18n (lower .Title)) | default .Title }} </h1>
     <ul>
       {{- range .Paginator.Pages -}}
         {{- .Render "li" -}}