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/jeu-video/2020-04-warzone-50-millions-joueurs/index.md

@@ -6,9 +6,10 @@ slug: "warzone-50-millions-joueurs"
 wordpress_id: 516
 excerpt: "6 millions de joueurs 24h après le lancement du jeu, 30 millions en 10 jours et 50 millions…\n"
 featured_image: "https://www.mistergeek.net/wp-content/uploads/2020/04/warzone.jpg"
-author: {"id":1,"name":"Kevin"}
-categories: [{"id":5,"name":"Jeu vidéo","slug":"jeu-video"}]
+author: "Kevin"
+categories: ["Jeu vidéo"]
 tags: []
+section: "jeu-video"
 ---
 
 </p>