Update Docs: Widgets “image” (#7005)

Author: rreo

website/content/docs/widgets/image.md

@@ -15,6 +15,7 @@ The image widget allows editors to upload an image or select an existing one fro
   * `allow_multiple`: *(default: `true`)* when set to `false`, multiple selection will be disabled even if the media library extension supports it
   * `config`: a configuration object passed directly to the media library; check the documentation of your media library extension for available `config` options
   * `media_folder` (Beta): file path where uploaded images will be saved specific to this control. Paths can be relative to a collection folder (e.g. `images` will add the image to a sub-folder in the collection folder) or absolute with reference to the base of the repo which needs to begin with `/` (e.g `/static/images` will save uploaded images to the `static` folder in a sub folder named `images`)
+  * `public_folder` *(defaults to the value of `media_folder`, with an opening `/` if one is not already included.)*: specifies the folder path where the files uploaded by the media library will be accessed, relative to the base of the built site. The value of the field is generated by prepending this path to the filename of the selected file.
   * `choose_url`: *(default: `true`)* when set to `false`, the "Insert from URL" button will be hidden
 * **Example:**
 
@@ -27,4 +28,4 @@ The image widget allows editors to upload an image or select an existing one fro
     media_library:
       config:
         multiple: true
-```
+```