 [Doctest] Add `configuration_clip.py`
Add `configuration_clip.py` to `utils/documentation_tests.txt` for doctest.

Based on issue #19487

Noticed the model initialization and config initialization lines were switched so made some additional changes to correct it.

@ydshieh could you please check if it's okay?
Thank you =)
_The documentation is not available anymore as the PR was closed or merged._<|||||>@daspartho Very cool!

Would you like to take the challenge to add doc example to `CLIPConfig`, which will use `from_text_vision_configs`. This will help a lot of the library users 🔥 Let me know :-)<|||||>@ydshieh Sure! I'd like to take on the task =)<|||||>@ydshieh made some changes; could you please check if it looks good?<|||||>@ydshieh added an example using the `from_text_vision_configs` method; could you please review the changes to see if they're okay? 
Thanks :)<|||||>Just a final comment and we are ready to merge!<|||||>@ydshieh made the suggested changes; good to go =)<|||||>Thank you for the PR and your patience :-) @daspartho 