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/streaming/2018-06-papystreaming-ne-fonctionne-plus/index.md

@@ -6,9 +6,10 @@ slug: "papystreaming-ne-fonctionne-plus"
 wordpress_id: 297
 excerpt: "Papystreaming, l’un des sites préférés des Français pour regarder du contenu en ligne ne fonctionne plus. Lorsqu’on parle…\n"
 featured_image: ""
-author: {"id":1,"name":"Kevin"}
-categories: [{"id":10,"name":"Streaming","slug":"streaming"}]
+author: "Kevin"
+categories: ["Streaming"]
 tags: []
+section: "streaming"
 ---
 
 <p><!--kg-card-begin: html--></p>