Add sections to keras3 test script

attachments/mnistKeras3.py

+# %% imports and versions
 import tensorflow as tf
 import keras
 from keras.models import Sequential
@@ -12,6 +13,7 @@ print('=========================')
 print(tf.config.list_physical_devices())
 print('=========================')
 
+# %% data, model, training, evaluation
 (X_train, y_train), (X_test, y_test) = mnist.load_data()
 
 X_train = X_train.reshape(60000, 28, 28, 1)
@@ -45,7 +47,7 @@ plt.tight_layout()
 plt.show()
 
 
-# import and load datasets to start the initial download
+# %% import and load datasets to start the initial download
 from sklearn.datasets import fetch_california_housing
 data = fetch_california_housing(as_frame=True)