Add example DAG and documentation for dataframe

[sunank200]

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Please describe the feature you'd like to see In the past, we had a tutorial which illustrated how to use each of our operators/decorators: https://github.com/astronomer/astro-sdk/blob/be6280df00ccff0d7a1c0dfb099b2065303dbe88/REFERENCE.md

Describe the solution you'd like Have a reference page per operator/decorator similar to https://airflow.apache.org/docs/apache-airflow-providers-amazon/stable/operators/ecs.html#howto-operator-ecsoperator

In which we reference parts of an (automated tested) example DAG which illustrates the usage of that operator/decorator.

Many of these use cases already exist in our example DAGs - we should reference them.

• dataframe
  • single example

Acceptance Criteria

• [x] dataframe
  • single example

• [x] All checks and tests in the CI should pass
• [x] Unit tests (90% code coverage or more, once available)
• [x] Integration tests (if the feature relates to a new database or external service)
• [x] Example DAG
• [x] Docstrings in reStructuredText for each of methods, classes, functions and module-level attributes (including Example DAG on how it should be used)
• [x] Exception handling in case of errors
• [x] Logging (are we exposing useful information to the user? e.g. source and destination)
• [x] Improve the documentation (README, Sphinx, and any other relevant)
• [x] How to use Guide for the feature (example)