Add build guide

build.md

@@ -0,0 +1,37 @@
+How to Build
+============
+
+The following steps should allow you to build this project:
+
+1. Make sure you have the lastest version of Node.js. On Ubuntu, you might
+   need a custom repository:
+
+   ```
+   sudo add-apt-repository ppa:chris-lea/node.js;
+   sudo apt-get update;
+   sudo apt-get install nodejs;
+   sudo apt-get upgrade;
+   ```
+
+2. Next hop into source directory where you cloned this repo. The following
+   commands will install grunt and all the Node dependencies:
+
+   ```
+   cd Wherever_You_Cloned/pen;
+   npm install;
+   sudo npm install -g grunt-cli;
+   ```
+
+3. Finally, you're ready to start a build:
+
+   ```
+   grunt;
+   ```
+
+   While editing a file, you can use `watch` to automatically rebuild every
+   time a file is saved:
+
+   ```
+   grunt watch;
+   ```
+