README.md in lisp-1.5.0 vs README.md in lisp-1.5.1

@@ -1,11 +1,11 @@
 lisp
 ====
 
-![Gem][1] ![Build Status][2]
+![Gem Version][3] ![Gem][1] ![Build Status][2]
 
-Lisp Interpreter in the Ruby Programming Language - 70 LOC. Inspired by [Lis.py](http://norvig.com/lispy.html).
+Minimal Lisp interpreter using 75LOC and only standard libraries excluding the REPL. Inspired by [Lis.py](http://norvig.com/lispy.html).
 
 ```clojure
 $ lisp-repl
 ctrl-c to exit
 > (begin                                                                        
@@ -18,14 +18,38 @@
 >                                      
 ```
 
 Install
 -------
-![Gem Version][3]
 
 ```
 gem install lisp
 ```
+
+Usage
+-----
+
+```clojure
+require "lisp"
+
+Lisp.eval(<<-eos)
+  (begin
+    (define fact
+      (lambda (n)
+        (if (<= n 1)
+          1
+          (* n (fact (- n 1))))))
+    (fact 10))
+eos # => 3628800
+```
+
+Commandline
+-----------
+
+```
+lisp-repl
+```
+
 
 Features
 --------
 
 - [x] __constant literal number__ -	A number evaluates to itself. _Example: 12 or -3.45e+6_