Update README.md

Author: simonsinclair

README.md

@@ -1,3 +1,40 @@
 # n32
 
 > Express numbers in a form that can be conveniently and accurately transmitted between humans and computers.
+
+## Install
+
+```sh
+npm i @simonsinclair/n32
+```
+
+## Usage
+
+```js
+const { default: n32 } = require('@simonsinclair/n32');
+
+const randomNumber = 123456789;
+const friendlyId = n32(randomNumber);
+
+console.log(friendlyId);
+```
+
+```js
+'3nqk8n';
+```
+
+## API
+
+### n32(number)
+
+Returns a string.
+
+#### number
+
+Type: `number`.
+
+The number to express.
+
+## Supported browsers
+
+IE11, and all modern browsers.