Auto merge of #31171 - dirk:dirk/safety-section-in-cstring-docs, r=steveklabnik
Auto merge of #31171 - dirk:dirk/safety-section-in-cstring-docs, r=steveklabnik

Also a minor language tweak to the documentation of the `ffi::CString::from_raw` function.

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