Add setter

Author: erikjanwestendorp

14/umbraco-cms/fundamentals/backoffice/property-editors/built-in-umbraco-property-editors/block-editor/block-grid-editor.md

@@ -623,7 +623,7 @@ public class BlockGridElementData
     public Udi Udi { get; }
 
     [JsonExtensionData]
-    public Dictionary<string, object>? Data { get; }
+    public Dictionary<string, object>? Data { get; set;}
 }
 ```
 {% endcode %}

15/umbraco-cms/fundamentals/backoffice/property-editors/built-in-umbraco-property-editors/block-editor/block-grid-editor.md

@@ -623,7 +623,7 @@ public class BlockGridElementData
     public Udi Udi { get; }
 
     [JsonExtensionData]
-    public Dictionary<string, object>? Data { get; }
+    public Dictionary<string, object>? Data { get; set;}
 }
 ```
 {% endcode %}