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/2023-05-investir-dans-un-ordinateur/index.md

@@ -6,9 +6,10 @@ slug: "investir-dans-un-ordinateur"
 wordpress_id: 5784
 excerpt: "Dans le monde moderne d’aujourd’hui, les ordinateurs sont devenus une partie essentielle de nos vies. Du divertissement à…\n"
 featured_image: "https://www.mistergeek.net/wp-content/uploads/2023/05/investir-dans-un-ordinateur-1.png"
-author: {"id":2,"name":"Expert"}
-categories: [{"id":14,"name":"Informatique","slug":"informatique"}]
+author: "Expert"
+categories: ["Informatique"]
 tags: []
+section: "informatique"
 ---
 
 </p>