es6 support

Author: gambitier

session 3/chapters/1. Software Package Manager.md

@@ -83,3 +83,39 @@ NPX stands for Node Package Executor. It is a new addition to NPM version 5.2.0
 There are more features that you can benefit from using NPX. Check this guide to learn more about NPX.
 
 for more information, [read here](https://www.section.io/engineering-education/npm-vs-yarn-which-one-to-choose/)
+
+# Metadata Inside package.json
+
+## The name property
+
+The `name property` in a `package.json` file is one of the fundamental components of the `package.json` structure. At its core, name is a string that is exactly what you would expect - the name of the module that the `package.json` is describing.
+
+Inside your `package.json`, the `name property` as a string would look something like this:
+
+## The main property
+
+It's the main entry point to your node package (library) for npm. It's needed if your npm project becomes a node package (library) which can be installed via npm by others.
+
+The `main property` of a `package.json` is a direction to the entry point to the module that the `package.json` is describing.
+
+In a Node.js application, when the module is called via a require statement, the module's exports from the file named in the `main property` will be what's returned to the Node.js application.
+
+Inside your `package.json`, the `main property`, with an entry point of `app.js`, would look like this:
+
+```
+"main": "app.js",
+```
+
+# Commonjs and ES6 modules
+
+![es6 module support](../images/es6-experimental.jpg)
+
+When you have `'type': 'module'` in the package.json file, your source code should use import syntax. When you do not have, you should use require syntax.
+
+- Adding `'type': 'commonjs'` to the package.json enables `commonjs` modules.
+
+![commonjs](../images/type-commonjs.jpg)
+
+- Adding `'type': 'module'` to the package.json enables `ES6` modules.
+
+![ES6](../images/type-es6.jpg)