Merge pull request #618 from mikeal/patch-1

Adding iojs to README.
diff --git a/README.markdown b/README.markdown
index 22e98ac..42bd831 100644
--- a/README.markdown
+++ b/README.markdown
@@ -71,6 +71,10 @@
     nvm install unstable
     nvm use stable
     nvm run unstable --version
+    
+If you want to install `io.js`:
+
+    nvm install iojs
 
 If you want to use the system-installed version of node, you can use the special default alias "system":