Collapse help into expandable command topics

plugins/checks/commands

@@ -3,12 +3,26 @@
 set -eo pipefail; [[ $DOKKU_TRACE ]] && set -x
 
 case "$1" in
-  help | ps:help)
-    cat<<EOF
+  help | checks:help)
+    help_content_func () {
+      declare desc="return help_content string"
+      cat<<help_content
     checks <app>, Show zero-downtime status
     checks:enable <app>, Enable zero-downtime checks
     checks:disable <app>, Disable zero-downtime checks
-EOF
+help_content
+    }
+
+    if [[ $1 = "checks:help" ]] ; then
+        echo -e 'Usage: dokku checks[:COMAND]'
+        echo ''
+        echo 'Manage zero-downtime checks.'
+        echo ''
+        echo 'Additional commands:'
+        help_content_func | sort | column -c2 -t -s,
+    else
+        help_content_func
+    fi
     ;;
 
   *)