Update Boot2docker information for OSX

README.md

@@ -59,7 +59,7 @@ docker run -d -p 4567:4567 --name slate -v $(pwd)/source:/app/source slate
 You can now see the docs at <http://localhost:4567>. Whoa! That was fast!
 
 *Note: if you're using the Docker setup on OSX, the docs will be
-availalable at the output of `boot2docker ip` instead of `localhost:4567`.*
+available at the output of `docker-machine ip <machine-name>` (port: 4567) instead of `localhost:4567`.*
 
 Now that Slate is all set up your machine, you'll probably want to learn more about [editing Slate markdown](https://github.com/tripit/slate/wiki/Markdown-Syntax), or [how to publish your docs](https://github.com/tripit/slate/wiki/Deploying-Slate).