Update broken link to Docker docs

site/plugin/plugin-how-it-works.md

@@ -23,7 +23,7 @@ If you do create additional networks using the `weavemesh` driver, containers at
 
 There's no specific documentation from Docker on using a cluster
 store, but the first part of
-[Getting Started with Docker Multi-host Networking](https://github.com/docker/docker/blob/master/docs/userguide/networking/get-started-overlay.md) is a good place to start.
+[Getting Started with Docker Multi-host Networking](https://docs.docker.com/engine/userguide/networking/get-started-overlay/) is a good place to start.
 
 >**Note:** In the case of multiple networks using the `weave` driver, all containers are on the same virtual network but Docker allocates their addresses on different subnets so they cannot talk to each other directly.