Added 1.4.0-pre.1 release notes (#1392)

Co-authored-by: Amy Reeve <amy.reeve@unity3d.com>
Co-authored-by: JiaRen <jia.ren@unity3d.com>

Author: 3 people

mppm/release-notes/release-notes.md

@@ -4,6 +4,16 @@ title: Release notes
 description: Release notes for Multiplayer Play Mode including new features, updates, bug fixes, and known issues.
 ---
 
+## [1.4.0-pre.1] - 2024-12-05
+
+### Fixed
+- Virtual Player windows correctly update and stay in sync when you enter and exit Play mode.
+- Removed instances of outdated internal build profile API functions.
+
+### Added
+- Added a Scenario launch pop-up window that shows the scenario stages, progress bars, and configuration details.
+- Added the Entities Hierarchy window to Virtual Players. To enable this window, go to **Layout** > **Entities Hierarchy**.
+
 ## [1.3.2] - 2024-11-14
 
 ### Fixed