Collapse help into expandable command topics

plugins/certs/commands

@@ -4,7 +4,9 @@ set -eo pipefail; [[ $DOKKU_TRACE ]] && set -x
 
 case "$1" in
   help | certs:help)
-    cat<<EOF
+    help_content_func () {
+      declare desc="return help_content string"
+      cat<<help_content
     certs:add <app> CRT KEY, Add an ssl endpoint to an app. Can also import from a tarball on stdin
     certs:chain CRT [CRT ...], [NOT IMPLEMENTED] Print the ordered and complete chain for the given certificate.
     certs:generate <app> DOMAIN, Generate a key and certificate signing request (and self-signed certificate)
@@ -13,7 +15,19 @@ case "$1" in
     certs:remove <app>, Remove an SSL Endpoint from an app.
     certs:rollback <app>, [NOT IMPLEMENTED] Rollback an SSL Endpoint for an app.
     certs:update <app> CRT KEY, Update an SSL Endpoint on an app. Can also import from a tarball on stdin
-EOF
+help_content
+    }
+
+    if [[ $1 = "certs:help" ]] ; then
+        echo -e 'Usage: dokku certs:COMMAND'
+        echo ''
+        echo 'Manage Dokku apps SSL (TLS) certs.'
+        echo ''
+        echo 'Additional commands:'
+        help_content_func | sort | column -c2 -t -s,
+    else
+        help_content_func
+    fi
     ;;
 
   *)