improve safe_copy slide a bit

lectures/user-experience/slides.qmd

@@ -416,12 +416,13 @@ if "?" in sys.argv:
 ```
 
 ## Hands-on {.handson}
-1. rewrite [safe_copy.py](static/safe_copy.py) to use intuitive argument names
+:::{.smaller}
+
+Rewrite [safe_copy.py](static/safe_copy.py) to use intuitive argument names, then make it more intuitive.
 ```python
 {{< include static/safe_copy.py >}}
 ```
-2. Make it more intuitive.
-
+:::
 # While running
 
 ## Escalate Errors {.special}