Use latest hipster tools to manage assets

doc/assets.markdown

@@ -5,21 +5,45 @@ Stylesheet and Javascript files are merged together and minified.
 
 - Original CSS files are stored in the folder `assets/css/src/*.css`
 - Original Javascript code is stored in the folder `assets/js/src/*.js`
+- `assets/*/vendor.min.*` are external dependencies merged and minified
+- `assets/*/app.min.*` are application source code merged and minified
 
 Requirements
 ------------
 
-- Unix operating system
-- make
-- yuicompressor in your path (`brew install yuicompressor`)
+- [NodeJS](https://nodejs.org/) with `npm`
 
-Build assets
-------------
+Building Javascript and CSS files
+---------------------------------
 
-- Build Stylesheet files: `make css`
-- Build Javascript files: `make js`
-- Build both: `make`
+Kanboard use [Gulp](http://gulpjs.com/) to build the assets and [Bower](http://bower.io/) to manage dependencies.
+These tools are installed as NodeJS dependencies into the project.
 
-This script generates the files `assets/css/app.css` and `assets/js/app.js`.
+### Run everything
 
-This tool is only available in the repository (development version).
+```bash
+make static
+```
+
+### Build `vendor.min.js` and `vendor.min.css`
+
+```bash
+gulp vendor
+```
+
+### Build `app.min.js`
+
+```bash
+gulp js
+```
+
+### Build `app.min.css`
+
+```bash
+gulp css
+```
+
+Notes
+-----
+
+Building assets is not possible from the Kanboard's archive, you have to clone the repository.