docs: update README with link to NPM

README.md

@@ -1,9 +1,13 @@
 # OFX JS
+
 Parse Open Financial Exchange (OFX) files into a usable data structure.
 
 For details on the OFX file format, download the latest specification from
 http://www.ofx.org/downloads.html
 
+[![NPM Version](https://img.shields.io/npm/v/ofx-js)](https://www.npmjs.com/package/ofx-js)
+![NPM Downloads](https://img.shields.io/npm/dm/ofx-js)
+
 # Goals
 
 * Work in the browser (no native code dependencies)
@@ -21,6 +25,12 @@ XML parser being used, it is not API-compatible and is probably slower.
 
 # Usage
 
+Installation:
+
+```sh
+npm install ofx-js
+```
+
 Example usage:
 
 ```javascript