[docs] Adds a doc on LoRA support for diffusers (#2086)
* add: a doc on LoRA support in diffusers.
* Apply suggestions from code review
Co-authored-by: Pedro Cuenca <pedro@huggingface.co>
* apply PR suggestions.
* Apply suggestions from code review
Co-authored-by: Pedro Cuenca <pedro@huggingface.co>
* remove visually incoherent elements.
Co-authored-by: Pedro Cuenca <pedro@huggingface.co>
