add more to the migration

Author: makspll

docs/src/Migration/0.14-to-0.15-alpha.md

@@ -165,4 +165,28 @@ pub enum Recipients {
 }
 ```
 
-This aligns with how scripts are associated with contexts better.
+This aligns with how scripts are associated with contexts better.
+
+## `ScriptCallbackEvent` changes
+
+The language for recipients is now controlled through the `language` field of the `ScriptCallbackEvent`. This allows for more flexibility in how callbacks are handled, especially when multiple languages are involved.
+
+If no language is specified, the callback will apply to all languages.
+
+```diff,ignore
+#[derive(Clone, Event, Debug)]
+#[non_exhaustive]
+pub struct ScriptCallbackEvent {
+    /// The label of the callback
+    pub label: CallbackLabel,
+    /// The recipients of the callback
+    pub recipients: Recipients,
+    /// The language of the callback, if unspecified will apply to all languages
+-   
++   pub language: Option<Language>
+    /// The arguments to the callback
+    pub args: Vec<ScriptValue>,
+    /// Whether the callback should emit a response event
+    pub trigger_response: bool,
+}
+```