Revert "Added ssh-keys default help function"

This reverts commit 74db5b9d3b.

plugins/ssh-keys/subcommands/default

@@ -1,12 +0,0 @@
-#!/usr/bin/env bash
-set -eo pipefail; [[ $DOKKU_TRACE ]] && set -x
-source "$PLUGIN_AVAILABLE_PATH/config/functions"
-source "$PLUGIN_AVAILABLE_PATH/ssh-keys/functions"
-
-ssh_keys_main_cmd() {
-  declare desc="return ssh-keys plugin help content"
-  local cmd="ssh-keys"
-  help_formatted
-}
-
-ssh_keys_main_cmd "$@"