When we make a plugin, we generally make the settings page but sometimes its difficult for admin to find where is the settings page for the plugin. For that we can add settings link to plugin list.

Use the code given below. Make sure to replace dcs-settings with the page url of your plugin.

/**
 * Filter to add settings link to 
 * plugins list page
 */
add_filter('plugin_action_links_'.plugin_basename(__FILE__), 'dcsPluginLinkListCallback');
function dcsPluginLinkListCallback( $links ) {
  $links[] = '<a href="' .
    admin_url( 'admin.php?page=dcs-settings' ) .
    '">' . __('Settings') . '</a>'; //replace dcs-settings with the page url of your plugin
  return $links;
}