Improve blog post display

* Add a post date to each post
* Do not show the post date for tours
* Only show posts tagged "current-event" on the home page (hiding 37c3 entries)
* Use a custom template for sorting the summary list by title (instead of the default by date)

content/de/38c3/_index.md

@@ -1,10 +1,15 @@
 ---
 title: 38c3 Touren
 weight: 10
-type: tours
+layout: list-bytitle
 menus:
   main:
     name: Touren
+params:
+  showPostDate: false
+cascade:
+  params:
+    showPostDate: false
 ---
 
 Diese Touren bieten wir zum 38c3 Chaos Communication Congress an: