docs(v2): add docs skeleton and structure (#1412)

* docs(v2): add docs skeleton and structure

* docs(v2): add on

* docs(v2): move motivation into contributing

website/docs/introduction.md

@@ -3,13 +3,33 @@ id: introduction
 title: Introduction
 ---
 
+<div className="alert alert--warning margin-vert--md" role="alert">
+  Docusaurus 2 is still <strong>work in progress</strong>. Do not use it in production yet!
+</div>
 
 ![Introducing Slash](/img/slash-introducing.svg)
 
 Docusaurus is a **painless static site generator** powered by React.
 
-
-## Installation
+## How it Works
 
 TODO
 
+## Features
+
+TODO
+
+## Is this the right tool for you?
+
+TODO - Comparison with other tools.
+
+- Next
+- Gatsby
+- React Static
+- Jekyll
+- GitBook
+
+#### References
+
+- https://reactjs.org/docs/getting-started.html
+- https://v1.vuepress.vuejs.org/guide/