feat(openapi): Add composer command

Signed-off-by: provokateurin <kate@provokateurin.de>

Author: provokateurin

composer.json

@@ -71,7 +71,8 @@
 		"test": "phpunit --configuration tests/phpunit-autotest.xml",
 		"test:db": "@composer run test -- --group DB,SLOWDB",
 		"test:files_external": "phpunit --configuration tests/phpunit-autotest-external.xml",
-		"rector": "rector --config=build/rector.php && composer cs:fix"
+		"rector": "rector --config=build/rector.php && composer cs:fix",
+		"openapi": "./build/openapi-checker.sh"
 	},
 	"extra": {
 		"bamarni-bin": {