fix(@schematics/update): add note that additional packages might require updating

Author: alan-agius4

packages/schematics/update/update/index.ts

@@ -530,6 +530,11 @@ function _usageMessage(
     logger.info('  ' + fields.map((x, i) => x.padEnd(pads[i])).join(''));
   });
 
+  logger.info(
+    `There might be additional packages which don't provide 'ng update' capabilities that are outdated.\n`
+    + `You can update the addition packages by running the update command of your package manager.`,
+  );
+
   return;
 }