[BUG]: 'keras.md' code refers erroneously to downloaded model file

[mdkeydama23]

Describe the bug
The current 'keras.md' code references the model file as 'keras_Model.h5', whereas the actual model file created and downloaded is named 'keras_model.h5'. This inconsistency is causing a runtime error in the program.

To Reproduce
Steps to reproduce the behavior:

1. Train model
2. Click on Export model
3. Navigate to 'Tensorflow'
4. Download model
5. Copy keras code snippet to local editor
6. Run code
7. Observe the runtime error

Relevant Links
Link to code to reproduce bug: https://github.com/googlecreativelab/teachablemachine-community/blob/master/snippets/markdown/image/tensorflow/keras.md

Expected behavior
The code should reference the model file as 'keras_model.h5' to match the actual filename, thus avoiding runtime errors.

Screenshots

Additional context
The inconsistency between the referenced model file name and the actual file name is causing confusion among users and resulting in runtime errors. Updating the code to accurately reflect the filename will resolve this issue.