style: improve readability of plot_static_generations doctest example

Author: Marioman2023

cellular_automata/von_neumann.py

@@ -466,7 +466,10 @@ def plot_static_generations(
         >>> history = simulate_von_neumann_cellular_automaton(
         ...     grid_rows=5, grid_columns=5, generations=10, random_seed=42
         ... )
-        >>> plot_static_generations(history, generations_to_show=[0, 2, 4, 6])  # doctest: +SKIP
+        >>> plot_static_generations(
+        ...     history,
+        ...     generations_to_show=[0, 2, 4, 6],  # doctest: +SKIP
+        ... )
     """
     if not generation_history:
         raise ValueError("generation_history cannot be empty")