docs(examples): add distinct and rest arg examples for ibis.intersect and Table.intersect

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Description of changes

Adds documentation examples to demonstrate rest and distinct usage for Table.intersect and ibis.intersect.

TODOs on difference and union examples

I don't think I realized until today that intersect, union, and difference can handle more than two table expressions at once. This is super convenient. I can add rest examples for the other two soon.

I'm not sure about putting together a distinct example for difference and union already has one.