adding notes how to get the HF models

[HamidShojanazeri]

What does this PR do?

Adding notes where to find HF models in addition to conversion step of the original weights.

Fixes # (issue)

Feature/Issue validation/testing

Please describe the tests that you ran to verify your changes and relevant result summary. Provide instructions so it can be reproduced.
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• Test A
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• Test B
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