Update changelog

Signed-off-by: Jiahao XU <Jiahao_XU@outlook.com>

Author: NobodyXu

src/changelog.rs

@@ -2,7 +2,9 @@
 use crate::*;
 
 /// TODO: RENAME THIS INTO THE NEXT VERSION BEFORE RELEASE
-///
+#[doc(hidden)]
+pub mod unreleased {}
+
 /// ## Fixed
 ///  - Remove accidentally exposed `TryFrom<tokio::process::ChildStdin`
 ///    implementation for [`ChildStdin`].
@@ -16,12 +18,12 @@ use crate::*;
 ///    implementation for [`ChildStderr`].
 ///  - Remove accidentally exposed `TryFrom<tokio_pipe::PipeRead>`
 ///    implementation for [`ChildStderr`].
-#[doc(hidden)]
+///
 /// ## Changed
 ///  - Make [`Session::check`] available only on unix.
 ///  - Make [`Socket::UnixSocket`] available only on unix.
 ///  - Make [`SessionBuilder::control_directory`] available only on unix.
-pub mod unreleased {}
+pub mod v0_9_0 {}
 
 /// ## Fixed
 ///  - Fixed changelog entry for rc2 not being visible