[Docs] Improve VLM docs (#33393)
* Improve docs
* Update docs/source/en/model_doc/llava.md
Co-authored-by: amyeroberts <22614925+amyeroberts@users.noreply.github.com>
* Update docs/source/en/model_doc/llava.md
Co-authored-by: amyeroberts <22614925+amyeroberts@users.noreply.github.com>
* Address comment
* Address comment
* Improve pixtral docs
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Co-authored-by: amyeroberts <22614925+amyeroberts@users.noreply.github.com>
