Add comment about UNPKG in readme.

README.md

@@ -14,17 +14,25 @@ npm install textures
 
 ## Usage
 
+Import `textures.js` from NPM with:
+
 ```
 import textures from 'textures';
 ```
 
-Or you can use `textures.js` in your html page with a `<script>` tag:
+You can also use`textures.js` in your html page with a `<script>` tag, dowloading `textures.js` in a local folder
 
 ```
 <script src="path/to/textures.js"></script>
 ```
 
-Then:
+or using the Unpkg CDN network
+
+```
+<script src="https://unpkg.com/[email protected]/dist/textures.js"></script>
+```
+
+Then `textures.js` can be used alongside with `d3` with:
 
 ```
 const svg = d3
@@ -44,4 +52,4 @@ svg
 
 ## License
 
-MIT
+MIT