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/informatique/2018-10-cloud-eco-operateur-telecom/index.md

@@ -6,9 +6,10 @@ slug: "cloud-eco-operateur-telecom"
 wordpress_id: 345
 excerpt: "Cloud Eco avis : téléphone, internet, une solution complète ! Disposer d’un réseau téléphonique complet et d’un accès…\n"
 featured_image: "https://www.mistergeek.net/wp-content/uploads/2018/10/cloud-eco.jpg"
-author: {"id":1,"name":"Kevin"}
-categories: [{"id":14,"name":"Informatique","slug":"informatique"}]
+author: "Kevin"
+categories: ["Informatique"]
 tags: []
+section: "informatique"
 ---
 
 <p><!--kg-card-begin: html--></p>