[INFERENCE PROVIDERS] function calling tutorial (#1832)
* first draft of function calling tutorial
* split hf client and openai for complex tool choice mode
* add guide to toc
* drop pointless hfoption
* remove excess hfoption markup
* Apply suggestions from text review
Co-authored-by: Sergio Paniego Blanco <sergiopaniegoblanco@gmail.com>
Co-authored-by: Pedro Cuenca <pedro@huggingface.co>
* clarify provider selection based on feedback
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Co-authored-by: Sergio Paniego Blanco <sergiopaniegoblanco@gmail.com>
Co-authored-by: Pedro Cuenca <pedro@huggingface.co>
