Remove mention of Box::default.

It is no longer treated specially. See #80 for details.

src/standard-library-types.md

@@ -1,10 +1,9 @@
 # Standard Library Types
 
 It is worth reading through the documentation for common standard library
-types—such as [`Box`], [`Vec`], [`Option`], [`Result`], and [`Rc`]/[`Arc`]—to find interesting
+types—such as [`Vec`], [`Option`], [`Result`], and [`Rc`]/[`Arc`]—to find interesting
 functions that can sometimes be used to improve performance.
 
-[`Box`]: https://doc.rust-lang.org/std/boxed/struct.Box.html
 [`Vec`]: https://doc.rust-lang.org/std/vec/struct.Vec.html
 [`Option`]: https://doc.rust-lang.org/std/option/enum.Option.html
 [`Result`]: https://doc.rust-lang.org/std/result/enum.Result.html
@@ -20,16 +19,6 @@ library types, such as [`Mutex`], [`RwLock`], [`Condvar`], and
 [`Condvar`]: https://doc.rust-lang.org/std/sync/struct.Condvar.html
 [`Once`]: https://doc.rust-lang.org/std/sync/struct.Once.html
 
-## `Box`
-
-The expression [`Box::default()`] has the same effect as
-`Box::new(T::default())` but can be faster because the compiler can create the
-value directly on the heap, rather than constructing it on the stack and then
-copying it over.
-[**Example**](https://github.com/komora-io/art/commit/d5dc58338f475709c375e15976d0d77eb5d7f7ef).
-
-[`Box::default()`]: https://doc.rust-lang.org/std/boxed/struct.Box.html#method.default
-
 ## `Vec`
 
 The best way to create a zero-filled `Vec` of length `n` is with `vec![0; n]`.