chore(classic-ui/images): add a code snippet

That showcases how to generate a responsive image with it `srcset`.

Author: gforcada

docs/classic-ui/images.md

@@ -291,6 +291,14 @@ Additionally, you can define [media queries](https://developer.mozilla.org/en-US
 The configuration allows you to define different picture variants, such as `Large`, `Medium`, or `Small`.
 Users can choose from them in editors, such as TinyMCE, and developers can use them in templates.
 
+To generate a `picture` tag, use:
+
+```python
+from plone import api
+
+scale_util = api.content.get_view("images", context, request)
+tag = scale_util.picture("image", scale='larger', picture_variant='large')
+```
 
 (classic-ui-images-responsive-image-support-picture-variants)=
 
@@ -533,4 +541,4 @@ This information shows we have everything we need to generate our image URLs, wi
     width="${python: preview['width']}"
     height="${python: preview['height']}" />
 </li>
-```
+```