Fix filename from model.py to data.py (#344)

Co-authored-by: Nicki Skafte Detlefsen <[email protected]>

s1_development_environment/deep_learning_software.md

@@ -215,7 +215,7 @@ future as you start to add more and more features. As subgoals, please fulfill t
 
     ??? example "Starting point for `data.py`"
 
-        ```python linenums="1" title="model.py"
+        ```python linenums="1" title="data.py"
         --8<-- "s1_development_environment/exercise_files/final_exercise/data.py"
         ```
 
@@ -236,7 +236,7 @@ future as you start to add more and more features. As subgoals, please fulfill t
         We have additionally in the solution added functionality for plotting the images together with the labels for
         inspection. Remember: all good machine learning starts with a good understanding of the data.
 
-        ```python linenums="1" hl_lines="17 18" title="model.py"
+        ```python linenums="1" hl_lines="17 18" title="data.py"
         --8<-- "s1_development_environment/exercise_files/final_exercise/data_solution.py"
         ```