Add various instructions

Author: dcodeIO

README.md

@@ -29,16 +29,32 @@ Usage
 
 The package exports an ECMAScript module with an UMD fallback.
 
+```sh
+$> npm install long
+```
+
 ```js
 import Long from "long";
 
-var longVal = new Long(0xFFFFFFFF, 0x7FFFFFFF);
-
-console.log(longVal.toString());
+var value = new Long(0xFFFFFFFF, 0x7FFFFFFF);
+console.log(value.toString());
 ...
 ```
 
-Note that mixing ESM and CommonJS is not recommended as it yield different classes with the same functionality.
+Note that mixing ESM and CommonJS is not recommended as it yields different classes, albeit with the same functionality.
+
+### Usage with a CDN
+
+  * From GitHub via [jsDelivr](https://www.jsdelivr.com):<br />
+    `https://cdn.jsdelivr.net/gh/dcodeIO/long.js@TAG/index.js` (ESM)
+  * From npm via [jsDelivr](https://www.jsdelivr.com):<br />
+    `https://cdn.jsdelivr.net/npm/long@VERSION/index.js` (ESM)
+    `https://cdn.jsdelivr.net/npm/long@VERSION/umd/index.js` (UMD)
+  * From npm via [unpkg](https://unpkg.com):<br />
+    `https://unpkg.com/long@VERSION/index.js` (ESM)
+    `https://unpkg.com/long@VERSION/umd/index.js` (UMD)
+
+  Replace `TAG` respectively `VERSION` with a [specific version](https://github.com/AssemblyScript/binaryen.js/releases) or omit it (not recommended in production) to use main/latest.
 
 API
 ---