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/2017-08-webtorrent-streaming/index.md

@@ -6,9 +6,10 @@ slug: "webtorrent-streaming"
 wordpress_id: 189
 excerpt: "Webtorrent est le logiciel, qui mixe le meilleur du monde torrent et du monde du Streaming. Parmi les…\n"
 featured_image: "https://www.mistergeek.net/wp-content/uploads/2017/08/webtorrent-bittorrent-gratuit.png"
-author: {"id":1,"name":"Kevin"}
-categories: [{"id":10,"name":"Streaming","slug":"streaming"}]
+author: "Kevin"
+categories: ["Streaming"]
 tags: []
+section: "streaming"
 ---
 
 </p>