Updated Scheduling Functions (markdown)

Scheduling-Functions.md

@@ -28,6 +28,9 @@ foo_cb()
 ```
 
 This schedules itself again when it runs, so it is always running. It runs, 10 minutes pass, it schedules itself again, and repeat. This is similar to JavaScript's [`setTimeout`](https://developer.mozilla.org/en-US/docs/Web/API/WindowOrWorkerGlobalScope/setTimeout).
+
+> **Important note**. Do **not** call the synchronous function when you schedule it, or it will recurse forever. `loop.call_later(delay, func())` won't work, but `loop.call_later(delay, func)` will.
+
 You can also use `while` loops:
 
 ```python