load_file() can handle pattern in file paths which is not explicit in document

[utkarsharma2]

Please describe the feature you'd like to see Currently, the feature of load_file() to handle patterns in the path is not clearly mentioned in the documentation and would be worth mentioning explicitly.

Describe the solution you'd like Add a section covering the pattern resolution feature in the load_file() operator.

Acceptance Criteria

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

[utkarsharma2]

cc: @mikeshwe

[phanikumv]

Lets do this by 1.2.1