add ticket purchase page

Co-authored-by: Jan-Marlon Leibl <jleibl@proton.me>
Reviewed-on: http://git.simonis.lol/projects/abiball/pulls/13
Reviewed-by: jank1619 <jan@kjan.email>

.ddev/config.yaml

@@ -7,8 +7,8 @@ xdebug_enabled: false
 additional_hostnames: []
 additional_fqdns: []
 database:
-    type: mariadb
-    version: "10.11"
+    type: postgres
+    version: "17"
 use_dns_when_possible: true
 composer_version: "2"
 web_environment: []