Add config block to media selector (#39696)

Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>

source/_docs/blueprint/selectors.markdown

@@ -1029,17 +1029,30 @@ You are prompted to select the device used to play media. Once the device is sel
 
 ![Screenshot of the Media selector](/images/blueprints/selector-media.png)
 
+To ask the user to select a media device and suitable media, you can use the
+media selector without any options:
+
 ```yaml
 media:
 ```
 
+You can also use the media selector with an optional `accept` filter to limit the
+media types that can be selected. The user will not be asked to pick a device.
+
 ```yaml
-# Do not ask for a device but manually specify a filter for the media.
 media:
   accept:
     - image/*
 ```
 
+{% configuration media %}
+accept:
+  description: >
+    List of media types the user is allowed to select.
+  type: list
+  required: false
+{% endconfiguration %}
+
 The output of the media selector, is an mapping with information about
 the selected media device and the selected media to play. There is also
 metadata, which is used by the frontend and should not be used in the
@@ -1181,7 +1194,7 @@ object:
   fields:
     name:
       label: Name
-      selector: 
+      selector:
         text:
     percentage:
       label: Percentage