Revert "Added certs default help function"

This reverts commit d001fcc896.

plugins/certs/subcommands/default

@@ -1,13 +0,0 @@
-#!/usr/bin/env bash
-set -eo pipefail; [[ $DOKKU_TRACE ]] && set -x
-source "$PLUGIN_CORE_AVAILABLE_PATH/common/functions"
-source "$PLUGIN_AVAILABLE_PATH/certs/functions"
-
-certs_main_cmd() {
-  declare desc="return certs plugin help content"
-  local cmd="certs"
-  help_formatted
-}
-
-certs_main_cmd "$@"
-