Add Entangling Gate to Documentation

[lazyoracle]

Describe the missing feature

Example notebook for Entangling Gates is not included in Documentation hosted on RTD

Describe the solution you'd like

Documentation for entangling gates similar to what we have for the other example notebooks (eg Model Learning)

Describe alternatives you've considered

Never read the docs because YOLO

Additional context

Add any other context or screenshots about the feature request here. Please feel free to suggest details about how you believe this feature request might be best implemented. If you have used similar features in other libraries, consider providing links or resources to example implementations.