Added MToon Example

Author: towneh

docs/avatar-shaders.mdx

@@ -8,6 +8,10 @@ title: Avatar Shaders
 - https://github.com/lilxyzw/lilToon
 ![image](https://booth.pximg.net/d39ea11b-78fc-488b-90dd-457109c7cd9b/i/3087170/235a98b9-7d60-49c5-980d-8028f6d0c6ad_base_resized.jpg)
 
+## MToon (MIT License) by UniVRM
+- https://github.com/vrm-c/UniVRM
+![image](https://vrm.dev/en/images/vrm/card.png)
+
 ## Sakura Shader (Membership) by Hyeve
 - https://ko-fi.com/sakurashaders 
 ![image](https://cdn.bsky.app/img/feed_fullsize/plain/did:plc:fxu7cua6kvrl7fz5fxso4cru/bafkreiad5qzfahj4yfrmljs7fgiztmjqsu4plfaenpeuaaxnga5ugfqkkm@jpeg)