refactor: update content structure and layout templates

- Updated author format in content files
- Added section field to content files
- Simplified categories format
- Removed no-category.html layout
- Updated list.html and single.html layouts
- Updated index.html layout
- Updated generate-content.js script
- Do not index content with git

content/telechargement/2018-11-steam-workshop/index.md

@@ -6,9 +6,10 @@ slug: "steam-workshop"
 wordpress_id: 351
 excerpt: "Besoin de télécharger un mod depuis le Workshop ? Vous souhaitez récupérer des addons ou des mods en…\n"
 featured_image: "https://www.mistergeek.net/wp-content/uploads/2018/11/steam.jpg"
-author: {"id":1,"name":"Kevin"}
-categories: [{"id":8,"name":"Téléchargement","slug":"telechargement"}]
+author: "Kevin"
+categories: ["Téléchargement"]
 tags: []
+section: "telechargement"
 ---
 
 </p>