Update README.md

Added prerequisites section from https://raw.githubusercontent.com/bromagosa/Ludus/master/README.md and made it clear that the repo needs to be _cloned_ instead of just using a zip file.

README.md

@@ -3,15 +3,33 @@ amber-examples
 
 Various amber examples
 
+
+
+Prerequisites
+=============
+
+1. A web browser with reasonably good support for HTML5 canvas.
+2. [nodejs](http://www.nodejs.org/). This will give you the node package manager `npm` as well.
+3. A global install of the [`amber`](http://amber-lang.net/) [npm](http://npmjs.org/) package
+4. A global install of the [`bower`](http://bower.io/) client side package manager in order to install the dependencies
+
+The `amber` and `bower` packages can be installed with the following command (In some cases you have to call `npm` with `sudo npm`):
+
+    npm install --global amber-cli bower
+
+or the same thing, but less typing:
+
+    npm i -g amber-cli bower
+
+Reference: http://docs.amber-lang.net/js-glossary.html
+
 Getting started
 ===============
 
-To get started you must first get the tools for this project:
-
-    npm install -g amber-cli
-    npm install -g bower
+Clone the repository 
+    git clone https://github.com/amber-smalltalk/amber-examples.git
 
- and dependencies of this project:
+Get dependencies of this project:
  
     git submodule update --init --recursive
     npm install