docs: fix broken link in dockerd.md
The Engine API docs are not available in this GitHub repository,
so linking to the docs.docker.com website instead.
@@ -124,7 +124,7 @@ the `daemon.json` file.
### Daemon socket option
-The Docker daemon can listen for [Docker Engine API](../api/)
+The Docker daemon can listen for [Docker Engine API](https://docs.docker.com/engine/api/)
requests via three different types of Socket: `unix`, `tcp`, and `fd`.
By default, a `unix` domain socket (or IPC socket) is created at
