Update README.md

Author: slyg

README.md

@@ -1,20 +1,31 @@
 #jscomplexity
 
 
-Command-line tool to generate a complexity report on file tree Javascript files. It is based on [complexityReport.js](https://github.com/philbooth/complexityReport.js) module results. Report stands in a .html file containing graphical representation of file tree.
+Command-line tool to generate a complexity report on file tree Javascript files. It is based on [complexityReport.js](https://github.com/philbooth/complexityReport.js) module results. Report stands in a .html file containing graphical representation of file tree when used from command-line.
 
-NB: /!\ Linux/OS compliant only for now.
+NB: **/!\** Linux/OS compliant only for now.
 
 
 ###Installation 
 
-<code>npm install -g jscomplexity</code>
+<code>npm install [-g] jscomplexity</code>
 
 
-###Usage
+###Command-line usage
 
 <code> $ jscr &lt;directory containing JS&gt; [optional : &lt;generated report directory, defaults current&gt;] </code>
 
 e.g.: 
 <code>$ jscr .</code>
 will generate report in current directory, using it as root for file tree walk-through.
+
+
+###Module usage
+
+<pre>
+var jscr = require('jscomplexity');
+
+jscr('/path/to/js/dir', function(err, report){
+  if (!err) console.log(report); 
+});
+</pre>