Add Makefile and remove the scripts directory

docs/assets.markdown

@@ -1,16 +1,24 @@
-How to build assets (Javascript and CSS files)?
-===============================================
+How to build assets (Javascript and CSS files)
+==============================================
 
 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`
 
-To make a new build run this shell-script from a terminal:
+Requirements
+------------
 
-```bash
-./scripts/make-assets.sh
-```
+- Unix operating system
+- make
+- yuicompressor in your path (`brew install yuicompressor`)
+
+Build assets
+------------
+
+- Build Stylesheet files: `make css`
+- Build Javascript files: `make js`
+- Build both: `make`
 
 This script generates the files `assets/css/app.css` and `assets/js/app.js`.