[Documentation] Add npm version badge to README

Author: MasterOdin

README.md

@@ -1,6 +1,7 @@
 # pdf-annotate.js
 
 [![Build Status](https://github.com/Submitty/pdf-annotate.js/workflows/Test/badge.svg?branch=master&event=push)](https://github.com/Submitty/pdf-annotate.js/actions?query=workflow%3ATest+event%3Apush+branch%3Amaster)
+[![npm version](https://img.shields.io/npm/v/@submitty/pdf-annotate.js)](https://npmjs.com/package/@submitty/pdf-annotate.js)
 [![codecov](https://codecov.io/gh/Submitty/pdf-annotate.js/branch/master/graph/badge.svg)](https://codecov.io/gh/Submitty/pdf-annotate.js)
 
 Annotation layer for [PDF.js](https://github.com/mozilla/pdf.js).