Merge pull request aws-amplify#4808 from nadetastic/js-getting-started

Update JS Getting Started steps to use `npm init` to create package.json

Author: nadetastic

src/fragments/start/getting-started/vanillajs/setup.mdx

@@ -2,49 +2,40 @@ Create a new ‘plain’ JavaScript <a href="https://babeljs.io/docs/en/learn/"
 
 ```bash
 mkdir -p amplify-js-app/src && cd amplify-js-app
-touch package.json index.html webpack.config.js src/app.js
+touch index.html src/app.js webpack.config.js
 ```
 
+Initialize npm and install dependencies and dev dependencies.
+
+```bash
+npm init
+npm install aws-amplify
+npm install webpack webpack-cli webpack-dev-server copy-webpack-plugin --save-dev
+```
+
+
 The app directory structure should be:
 
 ```console
 amplify-js-app
+├── node_modules/
+├── src/
+│   └── app.js
 ├── index.html
+├── package-lock.json
 ├── package.json
-├── src
-│   └── app.js
 └── webpack.config.js
 ```
 
-Add the following to the `package.json` file:
+Add the following scripts to the `package.json` file:
 
 ```json
-{
-  "name": "amplify-js-app",
-  "version": "1.0.0",
-  "description": "Amplify JavaScript Example",
-  "dependencies": {
-    "aws-amplify": "latest"
-  },
-  "devDependencies": {
-    "copy-webpack-plugin": "^6.1.0",
-    "webpack": "^4.46.0",
-    "webpack-cli": "^4.9.1",
-    "webpack-dev-server": "^4.4.0"
-  },
-  "scripts": {
+"scripts": {
     "start": "webpack && webpack-dev-server --mode development",
     "build": "webpack"
-  }
 }
 ```
 
-### Install local development dependencies
-
-```bash
-npm install
-```
-
 Add the following to the `index.html` file:
 
 ```html