add flush method

README.md

@@ -10,6 +10,8 @@ the fast log . This crate uses #! [forbid(unsafe_code)] to ensure everything is
 A log implementation for extreme speed, using Crossbeam to double the efficiency (as opposed to the standard library MPSC) with a lockless channel, using a channel to write logs asynchronously. Completely use the safe code to achieve, without safe code
 
 
+* Low overhead, based on May coroutines
+
 * High performance, use lockless message queue, log is stored in queue, then flush disk. It does not block the caller
 
 * Full APPEND mode file writing, high efficiency for solid state/mechanical disk (solid state and mechanical disk sequential write performance is better than random write)

README_CH.md

@@ -6,6 +6,7 @@ the fast log  . This crate uses #![forbid(unsafe_code)] to ensure everything is
 
 一款追求极致速度的日志实现，使用crossbeam 无锁channel提高一倍效率(相对于标准库的mpsc)，使用channel异步写日志。完全使用safe 代码实现，无不安全代码
 
+* 低开销，基于may协程
 * 高性能，使用无锁消息队列,日志先存于队列中，后续flush磁盘。不阻塞调用方
 * 全Append模式写入文件，对固态/机械磁盘效率高（固态以及机械硬盘 顺序写性能好于随机写）
 * 内置 Zip压缩，压缩文件名为日期+序号，无需操心日志文件过大