chore!: use pure ES modules

Author: ehmicky

.eslintrc.js renamed to .eslintrc.cjs

@@ -2,7 +2,11 @@ const { overrides } = require('@netlify/eslint-config-node')
 
 module.exports = {
   extends: '@netlify/eslint-config-node',
+  parserOptions: {
+    sourceType: 'module',
+  },
   rules: {
+    'import/extensions': [2, 'ignorePackages'],
     // TODO: enable those rules
     complexity: 0,
     'max-statements': 0,