add column for purpose of doc links

Author: willingc

doc-contributor/reference.md

@@ -2,15 +2,15 @@
 
 ## Links
 
-| Topic                                                                                              |
-| -------------------------------------------------------------------------------------------------- |
-| [nteract monorepo](https://github.com/nteract/nteract)                                             |
-| [React](https://reactjs.org/)                                                                      |
-| [React Docs - Main Concepts](https://reactjs.org/docs/hello-world.html)                            |
-| [Styleguidist](https://react-styleguidist.js.org/)                                                 |
-| [Styleguidist Docs - Getting Started](https://react-styleguidist.js.org/docs/getting-started.html) |
-| [Docusaurus](https://docusaurus.io/)                                                               |
-| [Docusaurus Docs - Installation](https://docusaurus.io/docs/en/installation)                       |
-| [now](https://zeit.co/now)                                                                         |
-| [Node.js - Download](https://nodejs.org/en/download/)                                              |
-| [Yarn - Getting Started](https://yarnpkg.com/en/docs/getting-started)                              |
+| Topic                                                                   | Why it's helpful                                                                            |
+|-------------------------------------------------------------------------|---------------------------------------------------------------------------------------------|
+| [nteract monorepo](https://github.com/nteract/nteract)                  | Source code for nteract desktop, packages, and components with READMEs for more information |
+| [React](https://reactjs.org/)                                           | The primary JavaScript framework uzed by nteract                                            |
+| [React Docs - Main Concepts](https://reactjs.org/docs/hello-world.html) | Official React docs                                                                         |
+| [Styleguidist](https://react-styleguidist.js.org/)                                                 | A tool used to create an interactive style guide for nteract components |
+| [Styleguidist Docs - Getting Started](https://react-styleguidist.js.org/docs/getting-started.html) | How to get started with Styleguidist tool |
+| [Docusaurus](https://docusaurus.io/)                                                               | A tool for creating documentation websites |
+| [Docusaurus Docs - Installation](https://docusaurus.io/docs/en/installation)                       | Installation of docusaurus |
+| [now](https://zeit.co/now)                                                                         | The service used to deploy our documentation and website |
+| [Node.js - Download](https://nodejs.org/en/download/)                                              | A project used for creating large concurrent JavaScript applicaiton |
+| [Yarn - Getting Started](https://yarnpkg.com/en/docs/getting-started)                              | Tool used for dependency deployment and builds |