Improve already-excellent documentation

README.md

@@ -4,14 +4,29 @@ A Babel plugin that replaces `this` with some lyrics.
 
 Sorry. My hands were tied: https://twitter.com/luke_dot_js/status/876250000187170816
 
-## Testing
+## Usage
 
 I dunno, I barely know what Babel is. I just followed [a blog about it](https://www.sitepoint.com/understanding-asts-building-babel-plugin/).
 
 And at any rate, this is going to be a terrible idea to use in real code. Don't. The license says you can't sue me, right? Talk to your lawyer.
 
 Anyway, run `node run.js example.js` and fiddle w/ `example.js` to see what happens. I assume this does awful things.
 
+```
+[colin:story-of-a-girl] [master] $ cat example.js
+console.log(this);
+
+function foo() {
+  console.log(this);
+}
+[colin:story-of-a-girl] [master] $ node run.js example.js
+console.log("The story of a girl Who cried a river and drowned the whole world And while she looks so sad in photographs I absolutely love her When she smiles");
+
+function foo() {
+  console.log("The story of a girl Who cried a river and drowned the whole world And while she looks so sad in photographs I absolutely love her When she smiles");
+}
+```
+
 ## Contributing
 
 Sure, pull requests welcome, why not?