chore: update CHANGELOG with virtio-net changes

Add `readv` and queue size increase changes in virtio-net
device to the CHANGELOG.

Signed-off-by: Egor Lazarchuk <[email protected]>

Author: ShadowCurse

CHANGELOG.md

@@ -10,10 +10,17 @@ and this project adheres to
 
 ### Added
 
+- [#4875](https://github.com/firecracker-microvm/firecracker/pull/4875): Increase
+  default queue size for the `virtio-net` device from 256 to 512. This decreases
+  wait time between guest and vmm threads for network packets processing and allows
+  for more throughput.
 - [#4834](https://github.com/firecracker-microvm/firecracker/pull/4834): Add
   `VIRTIO_NET_F_RX_MRGBUF` support to the `virtio-net` device. When this feature
   is negotiated, guest `virtio-net` driver can perform more efficient memory
   management which in turn improves RX and TX performance.
+- [#4844](https://github.com/firecracker-microvm/firecracker/pull/4844): Upgrade
+  `virtio-net` device to use `readv` syscall to avoid unnecessary memory copies
+  on RX path, increasing the RX performance.
 - [#4460](https://github.com/firecracker-microvm/firecracker/pull/4460): Add a
   call to
   [`KVM_KVMCLOCK_CTRL`](https://docs.kernel.org/virt/kvm/api.html#kvm-kvmclock-ctrl)