Add Option To Specify `openapitools.json` File Location

[AbbasCiatek]

We can specify the location of the generated openapitools.json file, by adding the --openapitools flag before the generate command.

 const command = [
                `npx openapi-generator-cli --openapitools=../../packages/sdk/openapitools.json generate`,
                `-g ${options.type}`,
                ...
];