use export default in cypress plugin file

packages/docs/cypress/plugins/index.js

@@ -16,7 +16,7 @@
  * @type {Cypress.PluginConfig}
  */
 // eslint-disable-next-line no-unused-vars
-// module.exports = (on, config) => {
+export default function cypressConfig(on, config) {
-// `on` is used to hook into various events Cypress emits
+  // `on` is used to hook into various events Cypress emits
-// `config` is the resolved Cypress config
+  // `config` is the resolved Cypress config
-// }
+}