Rollup merge of #42832 - rthomas:doc-fmt, r=steveklabnik
Rollup merge of #42832 - rthomas:doc-fmt, r=steveklabnik

Update docs for std::fmt::format #29355.

This rewords and removes the `Arguments` section from the docs for
fmt::format.

r? @steveklabnik

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