Add clarifying output

Added more output to clarify salsa example differences with copies vs pointers for lists.

Author: ndporter

_episodes/04-lists.md

@@ -129,15 +129,17 @@ does not.
 > the list value, it will change for both variables!
 >
 > ~~~
-> mlld_salsa = ['peppers', 'onions', 'cilantro', 'tomatoes']
+> mild_salsa = ['peppers', 'onions', 'cilantro', 'tomatoes']
 > hot_salsa = mild_salsa        # <-- mild_salsa and hot_salsa point to the *same* list data in memory
 > hot_salsa[0] = 'hot peppers'
 > print('Ingredients in mild salsa:', mild_salsa)
+> print('Ingredients in hot salsa:', hot_salsa)
 > ~~~
 > {: .language-python}
 >
 > ~~~
 > Ingredients in mild salsa: ['hot peppers', 'onions', 'cilantro', 'tomatoes']
+> Ingredients in hot salsa: ['hot peppers', 'onions', 'cilantro', 'tomatoes']
 > ~~~
 > {: .output}
 >
@@ -149,19 +151,21 @@ does not.
 > hot_salsa = list(mild_salsa)        # <-- makes a *copy* of the list
 > hot_salsa[0] = 'hot peppers'
 > print('Ingredients in mild salsa:', mild_salsa)
+> print('Ingredients in hot salsa:', hot_salsa)
 > ~~~
 > {: .language-python}
 >
 > ~~~
 > Ingredients in mild salsa: ['peppers', 'onions', 'cilantro', 'tomatoes']
+> Ingredients in hot salsa: ['hot peppers', 'onions', 'cilantro', 'tomatoes']
 > ~~~
 > {: .output}
 >
 > Because of pitfalls like this, code which modifies data in place can be more difficult to
 > understand. However, it is often far more efficient to modify a large data structure in place
 > than to create a modified copy for every small change. You should consider both of these aspects
 > when writing your code.
-{: .callout}
+> {: .callout}
 
 > ## Nested Lists
 > Since a list can contain any Python variables, it can even contain other lists.