content: Fix imported posts (markdown syntax, article types)

The auto-importer has created several issues with the markdown syntax which
needed manual fixing. Additionally quite a lot of event annoucements were
categorized as article.

content/blog/2003/2003-01-22-chaos-forschungslabor-magnet-und-chipkarte/index.md

@@ -1,7 +1,7 @@
 ---
 authors:
 - desc
-categories: article
+categories: event
 draft: false
 lastmod: '2003-01-22T15:10:36+01:00'
 publishDate: '2003-01-22T15:10:36+01:00'
@@ -15,4 +15,3 @@ Chaos-Forschungslabor statt. Dabei wird es keinen Vortrag geben, sondern
 \"freies Forschen am lebenden Objekt\". ;-) Diesmal geht es um Magnet-
 und Chipkarten in allen Varianten. Also bitte alle Karten mitbringen,
 die sich Zuhause so angesammelt haben!
-