Rollup merge of #64509 - varkor:convert-identity-doc-fixes, r=Centril
Rollup merge of #64509 - varkor:convert-identity-doc-fixes, r=Centril

Make some adjustments to the documentation for `std::convert::identity`

Fixes some extra blank lines and makes some minor tweaks to the wording.

aidancully/rust,aidancully/rust,graydon/rust,graydon/rust,aidancully/rust,graydon/rust,graydon/rust,aidancully/rust,graydon/rust,graydon/rust,aidancully/rust,aidancully/rust