2021 edition standard library prelude changes: address review comments

Author: mattheww

src/names/preludes.md

@@ -18,16 +18,15 @@ There are several different preludes:
 
 ## Standard library prelude
 
-Each crate has a standard library prelude, which consists of the names from a single standard library module. The module used depends on the crate's edition, and on whether the [`no_std` attribute] is applied to the crate:
+Each crate has a standard library prelude, which consists of the names from a single standard library module.
+The module used depends on the crate's edition, and on whether the [`no_std` attribute] is applied to the crate:
 
 Edition | `no_std` not applied        | `no_std` applied
 --------| --------------------------- | ----------------------------
 2015    | [`std::prelude::rust_2015`] | [`core::prelude::rust_2015`]
 2018    | [`std::prelude::rust_2018`] | [`core::prelude::rust_2018`]
 2021    | [`std::prelude::rust_2021`] | [`core::prelude::rust_2021`]
 
-This choice of prelude is in effect throughout the crate, including code generated by macros defined in crates with a different edition or `no_std` attribute.
-
 
 > **Note**:
 >
@@ -140,20 +139,20 @@ This attribute does not affect the [language prelude].
 
 [`alloc`]: ../../alloc/index.html
 [`Box`]: ../../std/boxed/struct.Box.html
-[`core::prelude::v1`]: ../../core/prelude/index.html
-[`core::prelude::rust_2015`]: ../../core/prelude/index.html
-[`core::prelude::rust_2018`]: ../../core/prelude/index.html
-[`core::prelude::rust_2021`]: ../../core/prelude/index.html
+[`core::prelude::v1`]: ../../core/prelude/v1/index.html
+[`core::prelude::rust_2015`]: ../../core/prelude/rust_2015/index.html
+[`core::prelude::rust_2018`]: ../../core/prelude/rust_2018/index.html
+[`core::prelude::rust_2021`]: ../../core/prelude/rust_2021/index.html
 [`core`]: ../../core/index.html
 [`extern crate`]: ../items/extern-crates.md
 [`macro_use` attribute]: ../macros-by-example.md#the-macro_use-attribute
 [`macro_use` prelude]: #macro_use-prelude
 [`no_std` attribute]: #the-no_std-attribute
 [`no_std` attribute]: #the-no_std-attribute
-[`std::prelude::v1`]: ../../std/prelude/index.html
-[`std::prelude::rust_2015`]: ../../std/prelude/index.html
-[`std::prelude::rust_2018`]: ../../std/prelude/index.html
-[`std::prelude::rust_2021`]: ../../std/prelude/index.html
+[`std::prelude::v1`]: ../../std/prelude/v1/index.html
+[`std::prelude::rust_2015`]: ../../std/prelude/rust_2015/index.html
+[`std::prelude::rust_2018`]: ../../std/prelude/rust_2018/index.html
+[`std::prelude::rust_2021`]: ../../std/prelude/rust_2021/index.html
 [`std`]: ../../std/index.html
 [`test`]: ../../test/index.html
 [attribute]: ../attributes.md