[xen staging] CHANGELOG.md: Start new 4.20.0 section

[patchbot@xxxxxxx]

commit a99f25f7ac60544e9af4b3b516d7566ba8841cc4
Author:     Julien Grall <julien@xxxxxxx>
AuthorDate: Thu Jul 18 16:51:02 2024 +0100
Commit:     Julien Grall <julien@xxxxxxx>
CommitDate: Thu Jul 18 16:51:02 2024 +0100

    CHANGELOG.md: Start new 4.20.0 section
    
    Signed-off-by: Julien Grall <julien@xxxxxxx>
---
 CHANGELOG.md | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index f8fbe82df6..c3b788df61 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,7 +4,15 @@ Notable changes to Xen will be documented in this file.
 
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 
-## 
[4.19.0](https://xenbits.xenproject.org/gitweb/?p=xen.git;a=shortlog;h=staging) 
- 2024-07-29
+## [4.20.0 
UNRELEASED](https://xenbits.xenproject.org/gitweb/?p=xen.git;a=shortlog;h=staging)
 - TBD
+
+### Changed
+
+### Added
+
+### Removed
+
+## 
[4.19.0](https://xenbits.xenproject.org/gitweb/?p=xen.git;a=shortlog;h=RELEASE-4.19.0)
 - 2024-07-29
 
 ### Changed
  - Changed flexible array definitions in public I/O interface headers to not
--
generated by git-patchbot for /home/xen/git/xen.git#staging