refactor: setup app domains in the post-create hook

This is more consistent with app setup, at the cost of making it so developers must disable domains manually afterwards.

plugins/domains/post-create

@@ -0,0 +1,19 @@
+#!/usr/bin/env bash
+source "$PLUGIN_AVAILABLE_PATH/domains/functions"
+set -eo pipefail
+[[ $DOKKU_TRACE ]] && set -x
+
+trigger-domains-post-create() {
+  declare desc="creates vhost files as necessary"
+  declare trigger="post-create"
+  declare APP="$1"
+
+  if [[ "$(is_app_vhost_enabled "$APP")" == "false" ]]; then
+    dokku_log_info1 "App virtual host support disabled, skipping domain setup"
+    return
+  fi
+
+  domains_setup "$APP"
+}
+
+trigger-domains-post-create "$@"