Update with -p as -D is deprecated now (OpenAPITools#5208)

docs/customization.md

@@ -224,7 +224,7 @@ apiPackage: "petstore"
 ```
 
 Supported config options can be different per language. Running `config-help -g {lang}` will show available options.
-**These options are applied via configuration file (e.g. config.json or config.yml) or by passing them with `-D{optionName}={optionValue}`**. (If `-D{optionName}` does not work, please open a [ticket](https://github.com/openapitools/openapi-generator/issues/new) and we'll look into it)
+**These options are applied via configuration file (e.g. config.json or config.yml) or by passing them with `-p {optionName}={optionValue}`**. (If `-p {optionName}` does not work, please open a [ticket](https://github.com/openapitools/openapi-generator/issues/new) and we'll look into it)
 
 ```sh
 java -jar modules/openapi-generator-cli/target/openapi-generator-cli.jar config-help -g java