Macro mf_plugin_with_config 

macro_rules! mf_plugin_with_config {
    (
        $name:ident,
        config = { $( $config_field:ident : $config_type:ty ),+ $(,)? },
        init_fn = $init_fn:expr
        $(, docs = $docs:expr )?
        $(,)?
    ) => { ... };
}

带配置支持的可配置插件宏