Add doc aliases for BStr and BString

Author: joshtriplett

alloc/src/bstr.rs

@@ -46,6 +46,7 @@ use crate::vec::Vec;
 #[unstable(feature = "bstr", issue = "134915")]
 #[repr(transparent)]
 #[derive(Clone)]
+#[doc(alias = "BString")]
 pub struct ByteString(pub Vec<u8>);
 
 impl ByteString {

core/src/bstr.rs

@@ -39,6 +39,7 @@ use crate::{fmt, hash};
 ///
 #[unstable(feature = "bstr", issue = "134915")]
 #[repr(transparent)]
+#[doc(alias = "BStr")]
 pub struct ByteStr(pub [u8]);
 
 impl ByteStr {