Add documentation on adding html attributes on img_tag liquid filter (#…

…2989)

src/OrchardCore.Modules/OrchardCore.Media/README.md

@@ -38,9 +38,8 @@ Renders an `<img src />` HTML tag.
 
 #### Options
 
-##### `alt` (Default)
-
-The alternate text attribute value
+You can add as many html attributes as you want with the img_tag.
+`{{ 'animals/kittens.jpg' | asset_url | img_tag: alt: 'kittens', class: 'kittens black', data_order: some_var }}`
 
 ## Image resizing filters
 
@@ -142,4 +141,4 @@ Keep these things in mind when working with the deployment step editor:
 https://sixlabors.com/projects/imagesharp/
 
 Copyright 2012 James South
-Licensed under the Apache License, Version 2.0
+Licensed under the Apache License, Version 2.0