Revise no_std intro WRT the preludes

We had text in the intro about "deferring to the core crate instead",
but it may not have been sufficiently clear what we mean exactly by
that.  Let's talk specifically about how `no_std` causes us to use the
`core` crate for the standard library prelude and for the `macro_use`
prelude.

Author: traviscross

src/names/preludes.md

@@ -81,7 +81,7 @@ r[names.preludes.extern.no_std]
 ### The `no_std` attribute
 
 r[names.preludes.extern.no_std.intro]
-The *`no_std` [attribute][attributes]* causes the [`std`] crate to not be linked automatically, deferring to the [`core`] crate instead.
+The *`no_std` [attribute][attributes]* causes the [`std`] crate to not be linked automatically, the [standard library prelude] to instead use the `core` prelude, and the [`macro_use` prelude] to instead use the macros exported from the `core` crate.
 
 > [!EXAMPLE]
 > <!-- ignore: test infrastructure can't handle no_std -->
@@ -183,7 +183,7 @@ r[names.preludes.no_implicit_prelude.edition2018]
 [Machine-dependent integer types]: ../types/numeric.md#machine-dependent-integer-types
 [Macro namespace]: namespaces.md
 [name resolution]: name-resolution.md
-[Standard library prelude]: #standard-library-prelude
+[standard library prelude]: names.preludes.std
 [Textual types]: ../types/textual.md
 [tool attributes]: ../attributes.md#tool-attributes
 [Tool prelude]: #tool-prelude