Fix OptionButton docs godotengine#36803

* item_selected and item_focused docs incorrectly had 'id' as the parameter. Changed to
'index'.
* Fix parameter name in ADD_SIGNAL callin code.

(cherry picked from commit a8de034f78198ba13fa7455d78e2ca31bb8b9f5f)

doc/classes/OptionButton.xml

@@ -214,14 +214,14 @@
 	</members>
 	<signals>
 		<signal name="item_focused">
-			<argument index="0" name="id" type="int">
+			<argument index="0" name="index" type="int">
 			</argument>
 			<description>
 				Emitted the when user navigates to an item using the [code]ui_up[/code] or [code]ui_down[/code] actions. The index of the item selected is passed as argument.
 			</description>
 		</signal>
 		<signal name="item_selected">
-			<argument index="0" name="id" type="int">
+			<argument index="0" name="index" type="int">
 			</argument>
 			<description>
 				Emitted when the current item has been changed by the user. The index of the item selected is passed as argument.

scene/gui/option_button.cpp

@@ -343,8 +343,8 @@ void OptionButton::_bind_methods() {
 	ADD_PROPERTY(PropertyInfo(Variant::ARRAY, "items", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_NOEDITOR | PROPERTY_USAGE_INTERNAL), "_set_items", "_get_items");
 	// "selected" property must come after "items", otherwise GH-10213 occurs.
 	ADD_PROPERTY(PropertyInfo(Variant::INT, "selected"), "_select_int", "get_selected");
-	ADD_SIGNAL(MethodInfo("item_selected", PropertyInfo(Variant::INT, "id")));
-	ADD_SIGNAL(MethodInfo("item_focused", PropertyInfo(Variant::INT, "id")));
+	ADD_SIGNAL(MethodInfo("item_selected", PropertyInfo(Variant::INT, "index")));
+	ADD_SIGNAL(MethodInfo("item_focused", PropertyInfo(Variant::INT, "index")));
 }
 
 OptionButton::OptionButton() {