Rollup merge of #114402 - tifv:tifv-fix-rc-doc, r=cuviper

Fix documentation of impl From<Vec<T>> for Rc<[T]>

The example in the documentation of `impl From<Vec<T>> for <Rc<[T]>` is irrelevant (likely was copied from `impl From<Box<T>> for <Rc<T>`). I suggest taking corresponding example from the documentation of `Arc` and replacing `Arc` with `Rc`.

Author: compiler-errors