Update formatting for site update post, clean up some date formatting and set front matter defaults.

_config.yml

@@ -28,3 +28,20 @@ category_titles:
   technology: "The Technologist"
   media: "The Player of Games"
   religion: "The Mystic"
+
+defaults:
+  - scope:
+      path: ""
+    values:
+      layout: default
+      author: Anna Wiggins
+  - scope:
+      path: ""
+      type: "posts"
+    values:
+      layout: post
+  - scope:
+      path: ""
+      type: "pages"
+    values:
+      layout: page