Add basic eslint setup.

Uses:

* Prettier
* eslint-plugin-node

Author: Robert Jackson

.eslintignore

@@ -0,0 +1,5 @@
+# do not ignore dotfiles
+!.*
+.git/
+
+/node_modules

.eslintrc.js

@@ -0,0 +1,21 @@
+module.exports = {
+  root: true,
+  parserOptions: {
+    ecmaVersion: 2019,
+    sourceType: 'script',
+  },
+  extends: ['eslint:recommended', 'plugin:node/recommended', 'plugin:prettier/recommended'],
+  plugins: ['prettier', 'node'],
+  env: {
+    node: true,
+  },
+  rules: {},
+  overrides: [
+    {
+      files: ['test/**/*.js'],
+      env: {
+        mocha: true,
+      },
+    },
+  ],
+};

.prettierrc

@@ -0,0 +1,5 @@
+{
+  "singleQuote": true,
+  "trailingComma": "es5",
+  "printWidth": 100
+}

package.json

@@ -17,7 +17,8 @@
     "ember-component-template-colocation-migrator": "./bin/ember-component-template-colocation-migrator"
   },
   "scripts": {
-    "test": "mocha test/*-test.js test/**/*-test.js"
+    "lint": "eslint .",
+    "test": "mocha test/**/*-test.js"
   },
   "dependencies": {
     "@babel/core": "^7.7.5",
@@ -36,12 +37,20 @@
   },
   "devDependencies": {
     "assert-diff": "^2.0.3",
+    "eslint": "^7.6.0",
+    "eslint-config-prettier": "^6.11.0",
+    "eslint-plugin-node": "^11.1.0",
+    "eslint-plugin-prettier": "^3.1.4",
     "fixturify": "^1.0.1",
     "mocha": "^6.1.1",
+    "prettier": "^2.0.5",
     "recast": "^0.19.1",
     "release-it": "^13.6.5",
     "release-it-lerna-changelog": "^2.3.0"
   },
+  "engines": {
+    "node": ">= 10"
+  },
   "publishConfig": {
     "registry": "https://registry.npmjs.org"
   },