Update docs for dockerd.md about `max-concurrent-downloads/max-concurrent-uploads`
It seems that `max-concurrent-downloads` and `max-concurrent-uploads`
are supported in Windows for `config.json`. Though that was not
mentioned in the docs for dockerd.md.
This fix adds the following to the example `config.json` file for Windows:
```
"max-concurrent-downloads": 3,
"max-concurrent-uploads": 5,
```
@@ -1208,6 +1208,8 @@ This is a full example of the allowed configuration options on Windows:
"graph": "",
"cluster-store": "",
"cluster-advertise": "",
+ "max-concurrent-downloads": 3,
+ "max-concurrent-uploads": 5,
"shutdown-timeout": 15,
"debug": true,
"hosts": [],
