Add README for model export functionality

[mzouink]

Added README.md for model export functionality, detailing export formats, usage examples, and integration with Hugging Face Hub.

Proposed Change

Briefly describe the contribution. If it resolves an issue or feature request, be sure to link to that issue.
Please also tag the PR with the appropriate labels (e.g. bugfix, feature, documentation, etc.)

Checklist

Go through these things before merge. Actions should run automatically to test them, but for information on how to run locally, see CONTRIBUTING.md.

• I have added tests that prove that my feature works in various situations or tests the bugfix (if applicable).
• I have checked that the tests pass and I maintained or improved test coverage (if applicable).
• I have written docstrings and checked that they render correctly in the documentation build.
• I have checked that mypy type checking passes.

Further Comments

If this is a relatively large or complex change, kick off the discussion by explaining why you chose the solution you did and what alternatives you considered, etc...