Fix broken link in asyncio thread safety docs (#2176)

* Fix broken link in asyncio thread safety docs

* Fix broken link in asyncio thread safety docs

docs/asyncio_thread_safety.md

@@ -6,7 +6,7 @@ Developing with asyncio requires careful attention to thread safety, as nearly a
 
 Home Assistant has some conventions for handling async and non-async code in the same code base. The top highlights are:
 
-- Deciding how to run a function from a helper depends on whether it is decorated with `@callback` to indicate it will not block and is safe to run in the event loop; for more details, see [Working with Async](asyncio_working_with_async).
+- Deciding how to run a function from a helper depends on whether it is decorated with `@callback` to indicate it will not block and is safe to run in the event loop; for more details, see [Working with Async](asyncio_working_with_async.md).
 - Most APIs have a sync and async version when calling a function from a thread. The async APIs are prefixed with `async_`. For example, when firing an event from a thread other than the event loop, use `hass.bus.fire` instead of `hass.bus.async_fire`.
 
 :::tip