liballoc docs: Remove “not intended for general usage”

Author: SimonSapin

src/liballoc/lib.rs

@@ -13,10 +13,10 @@
 //! This library provides smart pointers and collections for managing
 //! heap-allocated values.
 //!
-//! This library, like libcore, is not intended for general usage, but rather as
-//! a building block of other libraries. The types and interfaces in this
-//! library are re-exported through the [standard library](../std/index.html),
-//! and should not be used through this library.
+//! This library, like libcore, normally doesn’t need to be used directly
+//! since its contents are re-exported in the [`std` crate](../std/index.html).
+//! Crates that use the `#![no_std]` attribute however will typically
+//! not depend on `std`, so they’d use this crate instead.
 //!
 //! ## Boxed values
 //!