Add ability of displaying multiple authors on a blog post

[madcampos]

We want to change the way authors are listed to be an array of authors instead of a single entry, so the posts can list as written by multiple people.

This also needs tweaks to the AuthorCard component to make it responsive, using container queries, so the cards adapt to having either one single card, or having multiple cards next to each other.

Another point is to add a line to the PostHeader saying "by x and y" to list the authors of the post there.

[heem42]

I would like to take this up.

[madcampos]

@heem42 awesome!

We need to change then the schema to have multiple authors and then display them. The header part is easier, but we also want to add the author cards to the bottom of the post and that requires some thought on layout to better display them