howto: add index for fluentd doc
Add a link to the new fluentd document.
- [How to use Kata Containers and Containerd](containerd-kata.md)
- [How to use Kata Containers and CRI (containerd plugin) with Kubernetes](how-to-use-k8s-with-cri-containerd-and-kata.md)
- [Kata Containers and service mesh for Kubernetes](service-mesh.md)
+- [How to import Kata Containers logs into Fluentd](how-to-import-kata-logs-with-fluentd.md)
## Hypervisors Integration
- [Kata Containers with Firecracker](https://github.com/kata-containers/documentation/wiki/Initial-release-of-Kata-Containers-with-Firecracker-support)
