Add publications

[angristan]

• [x] Add publication form

• [x] Add publications on profile page

• [x] Add publications on home.php

• Likes?

• Comments?

[LAymeric]

@Angristan Did you ask our db teacher about the SQL query? (in order to display the posts in home.php)

I think we don't need the likes for the posts. And finally, I think we don't have time to add the ability to comment a post.