Install Node
Docular and the Grunt plugin for Docular are tools that runs in NodeJS.
NodeJS is built off of Google's JavaScript runtime environment. The original source for the AngularJS documentation generation was written for NodeJS so Docular followed suit.
The newest versions of NodeJS come bundled with NPM (Node Packaged Modules). NPM will be your friend and is a very powerful approach to managing dependencies within your project. The Docular NPM package depends on this system to install additional extensions that are managed through NPM.
mkdir myProj
cd myProj
npm init