Extend readme to explain install & run, #4

README.md

@@ -8,3 +8,26 @@ This implementation is a copycat of Scott Boland's [Java implementation](http://
 In cases where I could not grok the Java implementation easily I took ideas from the [LISP implementation](http://web.cecs.pdx.edu/~mm/how-to-get-copycat.html), or directly from [Melanie Mitchell](https://en.wikipedia.org/wiki/Melanie_Mitchell)'s "[Analogy-Making as Perception](http://www.amazon.com/Analogy-Making-Perception-Computer-Melanie-Mitchell/dp/0262132893/ref=tmm_hrd_title_0?ie=UTF8&qid=1351269085&sr=1-3)"
 
 I also tried to make the code more pythonic.
+
+Installation
+------------
+
+There are no particular installation instructions, just clone and run, e.g.
+
+    ```shell
+    $ git clone https://github.com/jalanb/co.py.cat.git
+    $ cd co.py.cat/copycat
+    $ python main.py abc abd ijk
+    ```
+
+Running
+-------
+
+The script takes three arguments.
+    The first two are a pair of triplets with some change, for example "abc" and "abd".
+    The third is a triplet which the script should try to change analogously
+
+For example the following invocation will probably display "ijl"
+    ```shell
+    $ python main.py abc abd ijk
+    ```