Rollup merge of #104965 - zacklukem:p-option-as_ref-docs, r=scottmcm

reword Option::as_ref and Option::map examples

The description for the examples of `Option::as_ref` and `Option::map` imply that the example is only doing type conversion, when it is actually finding the length of a string.

Changes the wording to imply that some operation is being run on the value contained in the `Option`

closes #104476

diff --cc library/core/src/option.rs
Simple merge