- Linting (ESLint): Check eslintrc file itself

- Linting: Add linting plugins (mocha, chai-expect, chai-friendly, cypress)
- Testing: Change cypress plugins file to ESM (so can set up any needed unit testing tasks)

cypress/plugins/main.js

@@ -0,0 +1,16 @@
+// This function is called when a project is opened or re-opened (e.g. due to
+// the project's config changing)
+
+import codeCoverageTask from '@cypress/code-coverage/task.js';
+
+// eslint-disable-next-line import/no-anonymous-default-export
+export default (on, config) => {
+  // `on` is used to hook into various events Cypress emits
+  // `config` is the resolved Cypress config
+
+  // `on` is used to hook into various events Cypress emits
+  // `config` is the resolved Cypress config
+
+  // https://docs.cypress.io/guides/tooling/code-coverage.html#Install-the-plugin
+  on('task', codeCoverageTask);
+};