Publish the Car Brain introduction and turn blog entries into cards - #25

Changed pages include:

• index.html - view
• 404.html - view
• 404/index.html - view
• _not-found/index.html - view
• blog/index.html - view
• colophon/index.html - view
• pl/index.html - view
• blog/pl/index.html - view
• look/standard-dark/index.html - view
• look/standard-light/index.html - view

There are more changes not included in the list