Add changelog entry for GDB debugging

Add an entry for the new microVM guest kernel debugging feature

Signed-off-by: Jack Thomson <jackabt@amazon.com>

CHANGELOG.md

@@ -26,6 +26,10 @@ and this project adheres to
 - [#4869](https://github.com/firecracker-microvm/firecracker/pull/4869): Added
   support for Aarch64 systems which feature CPU caches with a number of sets
   higher than `u16::MAX`.
+- [#4797](https://github.com/firecracker-microvm/firecracker/pull/4797),
+  [#4854](https://github.com/firecracker-microvm/firecracker/pull/4854): Added
+  GDB debugging support for a microVM guest kernel. Please see our
+  [GDB debugging documentation](docs/gdb-debugging.md) for more information.
 
 ### Changed