Add contact backend and update readme

contact-backend/config.php

@@ -0,0 +1,11 @@
+<?php
+
+$allowed_origins = ["localhost", "chill.social", "www.chill.social"];
+$smtp_host = "mailpit";
+$smtp_port = 1025;
+$smtp_user = "chill-website@champs-libres.coop";
+$smtp_password = "lalalala";
+$smtp_from = "chill-website@champs-libres.coop";
+$smtp_to = "damien.mercier@champs-libres.coop";
+$smtp_secure = false;
+$debug = true;