I used the code from codelab repository for visualization and loading the data, and I added the files:

1. mnist_final_conv.py --> main python file
2. neural_network/init.py --> initialization of the learning rate, placeholders and weights
3. neural_network/layers.py --> includes functions that create layers withe their weights
4. neural_network/model.py --> includes functions that create a complete network model
5. neural_network/optimizer.py --> include functions that create the training step