fix: updated utility link to npm

Author: dackers86

docs/image-processing-api/index.mdx

@@ -149,4 +149,4 @@ const output = builder()
 console.log(output.toJSON());
 ```
 
-For more details, [view the documentation](/utility-library).
+For more details, [view the documentation](https://www.npmjs.com/package/@invertase/image-processing-api).