function isProvidedTemplateRendererSupported(templateConfig) {
  const supportedRenderers = [undefined, 'react', 'nunjucks'];
  if (supportedRenderers.includes(templateConfig.renderer)) {
    return;
  }

  throw new Error(`We do not support '${templateConfig.renderer}' as a renderer for a template. Only 'react' or 'nunjucks' are supported.`);
}
Checks if the the provided renderer are supported (no renderer are also supported, defaults to nunjucks)

@param  {Object} templateConfig Template configuration.