DOC: Add dns as an available domain to show stat

Within management.txt, proxy was listed as the only available option. "dns"
is now supported so let's add that. This change also updates the command to list
the available options <dns|proxy> for "domain" as previously it only specified
<domain>, which could be confusing as a user may think this field accepts
dynamic options when it actually requires a specific keyword.
1 file changed