Yes, they work just like on GitHub.com.
Links in Markdown are rewritten to link to HTML pages:
something.mdwill be rewritten to
Something-Else.mdwill be rewritten to
CONTRIBUTING.mdwill be rewritten to
README.mdwill be rewritten to
Probably not yet, but you are welcome to try. PHP-DI's website has a pseudo-blog where the article list is written manually: it's possible, but not (yet) super easy.
It is planned! In the meantime, you can simply use
couscous generate and upload the files to your webserver manually.
Because Couscous is good, and so is this.