Fix base_template name in example

docs/topics/3.0-announcement.md

@@ -826,7 +826,7 @@ The `style` keyword argument can be used to pass through additional information
 For example, to use a `textarea` control instead of the default `input` control, you would use the following…
 
     additional_notes = serializers.CharField(
-        style={'base_template': 'text_area.html'}
+        style={'base_template': 'textarea.html'}
     )
 
 Similarly, to use a radio button control instead of the default `select` control, you would use the following…