Lint all Markdown documents

Signed-off-by: David Gageot <david@gageot.net>

docs/reference/index.md

@@ -9,25 +9,24 @@ parent="smn_machine_ref"
 +++
 <![end-metadata]-->
 
-
 # Supported Docker Machine subcommands
 
-* [active](active.md)
-* [config](config.md)
-* [create](create.md)
-* [env](env.md)
-* [help](help.md)
-* [inspect](inspect.md)
-* [ip](ip.md)
-* [kill](kill.md)
-* [ls](ls.md)
-* [regenerate-certs](regenerate-certs.md)
-* [restart](restart.md)
-* [rm](rm.md)
-* [scp](scp.md)
-* [ssh](ssh.md)
-* [start](start.md)
-* [status](status.md)
-* [stop](stop.md)
-* [upgrade](upgrade.md)
-* [url](url.md)
+-   [active](active.md)
+-   [config](config.md)
+-   [create](create.md)
+-   [env](env.md)
+-   [help](help.md)
+-   [inspect](inspect.md)
+-   [ip](ip.md)
+-   [kill](kill.md)
+-   [ls](ls.md)
+-   [regenerate-certs](regenerate-certs.md)
+-   [restart](restart.md)
+-   [rm](rm.md)
+-   [scp](scp.md)
+-   [ssh](ssh.md)
+-   [start](start.md)
+-   [status](status.md)
+-   [stop](stop.md)
+-   [upgrade](upgrade.md)
+-   [url](url.md)