Fix tab
Add <aside> around image post metadata
Add <figure> and <figcaption> to image posts

* Move <h1> to the top, will be hidden by CSS
* Repeat title in the <figcaption>, to be styled similarly as <h1> elsewere
Fix </aside> in image posts
Make featured image full-width on narrow viewports
Follow-up on previous commit with generated CSS
Implement content templates for posts & projects
Refactor image post template a bit, prioritize content
Add portrait or landscape class to image posts
Cleaner ifs