Merge pull request #368 from grahamwhaley/20190130_fc_link

docs: firecracker: add top level link off to fc wiki page

Author: caoruidong

README.md

@@ -19,6 +19,7 @@ For details of the other Kata Containers repositories, see the
 
 * HOWTO: [Kata Containers with k8s and cri-containerd](./how-to/how-to-use-k8s-with-cri-containerd-and-kata.md)
 * HOWTO: [OpenStack Zun with Kata Containers](zun/zun_kata.md)
+* HOWTO: [Kata Containers with Firecracker](https://github.com/kata-containers/documentation/wiki/Initial-release-of-Kata-Containers-with-Firecracker-support)
 
 ## Developer Guide