Use JSON for config files

Towards getting rid of CommonJS

.eslintrc.js

-module.exports = {
-  env: {
-    browser: true,
-    es6: true,
-    node: true,
-    jest: true,
-  },
-  extends: "eslint:recommended",
-  globals: {
-    Atomics: "readonly",
-    SharedArrayBuffer: "readonly",
-  },
-  parserOptions: {
-    ecmaVersion: 2018,
-    sourceType: "module",
-  },
-  rules: {},
-}