docs: fix missing list prefix for --security-opt label entry

The --security-opt label flag was added by #4639 but was indented as a
continuation of the apparmor line rather than its own list item. Add the
missing '- ' prefix to restore consistent Markdown formatting.

Partial fix for #3867

Signed-off-by: Ogulcan Aydogan <ogulcanaydogan@hotmail.com>

Author: ogulcanaydogan

docs/command-reference.md

@@ -255,7 +255,7 @@ Security flags:
 
 - :whale: `--security-opt seccomp=<PROFILE_JSON_FILE>`: specify custom seccomp profile
 - :whale: `--security-opt apparmor=<PROFILE>`: specify custom AppArmor profile
-  :whale: `--security-opt label=<selinuxlabel>`: specify custom selinux label
+- :whale: `--security-opt label=<selinuxlabel>`: specify custom selinux label
 - :whale: `--security-opt no-new-privileges`: disallow privilege escalation, e.g., setuid and file capabilities
 - :whale: `--security-opt systempaths=unconfined`: Turn off confinement for system paths (masked paths, read-only paths) for the container
 - :whale: `--security-opt writable-cgroups`: making the cgroups writeable