docs: fix link to VecDeque by replacing std with alloc

src/with_alloc/vecdeque.rs

@@ -5,7 +5,7 @@ use alloc::collections::VecDeque;
 use core::ops::{Deref, DerefMut, Index, IndexMut};
 
 /// A growable ringbuffer. Once capacity is reached, the size is doubled.
-/// Wrapper of the built-in [`VecDeque`](std::collections::VecDeque) struct
+/// Wrapper of the built-in [`VecDeque`](alloc::collections::VecDeque) struct
 ///
 /// The reason this is a wrapper, is that we want `RingBuffers` to implement `Index<isize>`,
 /// which we cannot do for remote types like `VecDeque`