doc: local trees parameter documentation

[ethanglaser]

Description

Follow-up to #2615 (and uxlfoundation/oneDAL#3139). Adds documentation of additional parameter to SPMD forest estimators. Open to discussion on the best way to do this since I don't believe we have any prior references for this.

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[david-cortes-intel]

@ethanglaser The only section that I'm aware of where extra parameters are documented is here:
https://uxlfoundation.github.io/scikit-learn-intelex/2025.7/guide/acceleration.html#random-forest

The title of the doc section doesn't match at all with the contents, but perhaps you could put it there for now next to the other extra parameters of decision trees, and then later we can revisit the structuring of the docs.