Fix typo

Author: miyakogi

pyppeteer/frame_manager.py

@@ -571,7 +571,7 @@ async def click(self, selector: str, options: dict = None, **kwargs: Any
  await handle.dispose()
 
  async def focus(self, selector: str) -> None:
- """Fucus element which matches ``selector``.
+ """Focus element which matches ``selector``.
 
  Details see :meth:`pyppeteer.page.Page.focus`.
  """