Update README

README.md

@@ -1,10 +1,13 @@
 # babel-preset-es2015-node
+[![npm version][npm-badge]][npm-href]
 
 > Babel preset for the minimum necessary `babel-preset-es2015` plugins needed for your version of node
 
 This preset automatically determines which version of node you are using via `process.version` and sets the minimum necessary `babel-preset-es2015` plugins accordingly.
 
-All versions of node >=4 are supported.
+All versions of node ≥4 are supported.
+
+*Note: the major version of this package corresponds to the compatible major version of Babel (i.e. use `babel-preset-es2015-node@6` with `babel-cli@6`*.
 
 ## Install
 ```sh
@@ -36,3 +39,6 @@ require("babel-core").transform("code", {
   presets: ["es2015-node"]
 });
 ```
+
+[npm-badge]: https://badge.fury.io/js/babel-preset-es2015-node.svg
+[npm-href]: https://www.npmjs.com/package/babel-preset-es2015-node