Auto merge of #11051 - EstebanBorai:fix/specify-crate-name-maxlength,…

… r=weihanglo

fix: specifies the max length for crate name

Provides the maximum length on the crate name as is defined
in the [crate's validation source code from crates.io][1].

[1]: https://github.com/rust-lang/crates.io/blob/3fc08ba57e782cff422a2f92503f09287d1a5140/src/models/krate.rs#L74

src/doc/src/reference/manifest.md

@@ -74,11 +74,15 @@ when listed as a dependency in another package, and as the default name of
 inferred lib and bin targets.
 
 The name must use only [alphanumeric] characters or `-` or `_`, and cannot be empty.
+
 Note that [`cargo new`] and [`cargo init`] impose some additional restrictions on
 the package name, such as enforcing that it is a valid Rust identifier and not
-a keyword. [crates.io] imposes even more restrictions, such as
-enforcing only ASCII characters, not a reserved name, not a special Windows
-name such as "nul", is not too long, etc.
+a keyword. [crates.io] imposes even more restrictions, such as:
+
+- Only ASCII characters are allowed.
+- Do not use reserved names.
+- Do not use special Windows name such as "nul".
+- Use a maximum of 64 characters of length.
 
 [alphanumeric]: ../../std/primitive.char.html#method.is_alphanumeric