api_refs.sh: Increase verbosity

Author: adriendupuis

tools/api_refs/api_refs.sh

@@ -1,6 +1,6 @@
 #!/usr/bin/env bash
 
-set +x;
+set -x;
 
 AUTH_JSON=${1:-~/.composer/auth.json}; # Path to an auth.json file allowing to install the targeted edition and version
 PHP_API_OUTPUT_DIR=${2:-./docs/api/php_api/php_api_reference}; # Path to the directory where the built PHP API Reference is hosted