Document `OptimizedTranslation.generate()` only works in editor

doc/classes/OptimizedTranslation.xml

@@ -14,6 +14,7 @@
 			<param index="0" name="from" type="Translation" />
 			<description>
 				Generates and sets an optimized translation from the given [Translation] resource.
+				[b]Note:[/b] This method is intended to be used in the editor. It does nothing when called from an exported project.
 			</description>
 		</method>
 	</methods>