use nested note

Author: HumphreyYang

lectures/jax_intro.md

@@ -301,7 +301,7 @@ the device. This is necessary because JAX uses asynchronous dispatch, which
 allows the Python interpreter to run ahead of GPU computations.
 ```
 
-```{note}
+````{note}
 Here, we use the [`%timeit` magic](https://ipython.readthedocs.io/en/stable/interactive/magics.html#magic-timeit)
 to time the execution of the function. 
 
@@ -324,7 +324,7 @@ The `%timeit` magic command offers several advantages over `%time`:
 However, `%timeit` can be time-consuming for large computations.
 
 This is why we switch to using `%time` in later lectures.
-```
+````
 
 The code doesn't run as fast as we might hope, given that it's running on a GPU.