don't add initialization edits to undo stack

Author: amunger

src/vs/workbench/contrib/notebook/common/model/notebookTextModel.ts

@@ -402,7 +402,7 @@ export class NotebookTextModel extends Disposable implements INotebookTextModel
 			true,
 			undefined, () => undefined,
 			undefined,
-			true
+			false
 		);
 	}