Update 'README.md'

README.md

 
 Install:
 
-	npm install --save webframe
+```
+npm install --save webframe
+```
 
 Use:
 
-	var webframe = require("webframe");
-	var app = new webframe.App();
+```
+var webframe = require("webframe");
+var app = new webframe.App();
+```
 
 The file example.js contains an example of a small web application.
 
 * `res403`: The string to return for a 403 error. "{{pathname}}" will be
   replaced with the pathname.
 
-	var app = webframe.App({ client_utils: true });
+```
+var app = new webframe.App({ client_utils: true });
+```
 
 ### app.route(method, path [, middleware], func)