docs: use "console" code-hint for shell examples

This replaces the use of bash where suitable, to allow easier copy/pasting
of shell examples without copying the prompt or process output.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

docs/reference/commandline/node_promote.md

@@ -28,7 +28,7 @@ Promotes a node to manager. This command can only be executed on a manager node.
 
 ## Examples
 
-```bash
+```console
 $ docker node promote <node name>
 ```