add watch feature in docs and changelog for v2.2.2

Author: roseduan

CHANGELOG.md

@@ -1,3 +1,23 @@
+# Release 2.2.2(2023-08-05)
+## 🚀 New Features
+* Watch Key [feature support watch event by key #227](https://github.com/rosedblabs/rosedb/issues/227) @Jeremy-Run 
+
+## 🎄 Enhancements
+
+* Batch Optimiztion [use sync.Pool to optimize db.Put operation #235](https://github.com/rosedblabs/rosedb/issues/235)
+* Optimize memory usage [enhancement: high memory usage of rosedb #236](https://github.com/rosedblabs/rosedb/issues/236)
+
+## 🎠 Community
+* Thanks to @kebukeYi 
+    * Change Variable name in openMergeDB (https://github.com/rosedblabs/rosedb/pull/228)
+    * Avoid parsing wal files repeatedly. (https://github.com/rosedblabs/rosedb/pull/229)
+* Thanks to @Jeremy-Run 
+    * Deleted data cannot exist in the index (https://github.com/rosedblabs/rosedb/pull/232)
+    * fix: solve data race (https://github.com/rosedblabs/rosedb/pull/234)
+    * fix: destFile may be not exist (https://github.com/rosedblabs/rosedb/pull/243)
+* Thanks to @rfyiamcool 
+    * fix: format code comment for rand_kv (https://github.com/rosedblabs/rosedb/pull/240)
+
 # Release 2.2.1(2023-07-03)
 
 ## 🎠 Community

README-CN.md

@@ -75,6 +75,11 @@ RoseDB 存储数据的文件使用预写日志（Write Ahead Log），这些日
     RoseDB 支持正向和反向迭代器，这些迭代器可以在数据库中的任何位置开始迭代。迭代器可以用于扫描数据库中的所有键值对，也可以用于扫描数据库中的某个范围的键值对，迭代器从索引中获取位置信息，然后直接从磁盘中读取数据，因此迭代器的性能非常高。
 </details>
 
+<details>
+    <summary><b>支持 Watch 功能</b></summary>
+    RoseDB 支持 Watch 功能，DB 中的 key 发生变化时你可以得到一个事件通知。
+</details>
+
 ### 缺点
 
 <details>

README.md

@@ -76,6 +76,11 @@ RoseDB log files are using the WAL(Write Ahead Log) as backend, which are append
 	RoseDB supports iterator for forward and backward. The iterator is based on the in-memory index data structure of keys, which points directly to locations on disk where the data lives. The iterator is very efficient, even when datasets are very large.
 </details>
 
+<details>
+    <summary><b>Support key watch</b></summary>
+	RoseDB supports key watch, you can get the notification if keys changed in db.
+</details>
+
 ### Weaknesses
 
 <details>