releases: add tidb 5.2.3 release note (pingcap#7061)

TOC.md

@@ -577,6 +577,7 @@
   - v5.3
     - [5.3.0](/releases/release-5.3.0.md)
   - v5.2
+    - [5.2.3](/releases/release-5.2.3.md)
     - [5.2.2](/releases/release-5.2.2.md)
     - [5.2.1](/releases/release-5.2.1.md)
     - [5.2.0](/releases/release-5.2.0.md)

releases/release-5.2.3.md

@@ -0,0 +1,15 @@
+---
+title: TiDB 5.2.3 Release Note
+---
+
+# TiDB 5.2.3 Release Note
+
+Release date: December 3, 2021
+
+TiDB version: 5.2.3
+
+## Bug fix
+
++ TiKV
+
+    - Fix the issue that the `GcKeys` task does not work when it is called by multiple keys. Caused by this issue, compaction filer GC might not drop the MVCC deletion information. [#11217](https://github.com/tikv/tikv/issues/11217)

releases/release-notes.md

@@ -11,6 +11,7 @@ aliases: ['/docs/dev/releases/release-notes/','/docs/dev/releases/rn/']
 
 ## 5.2
 
+- [5.2.3](/releases/release-5.2.3.md)
 - [5.2.2](/releases/release-5.2.2.md)
 - [5.2.1](/releases/release-5.2.1.md)
 - [5.2.0](/releases/release-5.2.0.md)

releases/release-timeline.md

@@ -9,6 +9,7 @@ This document shows all the released TiDB versions in reverse chronological orde
 
 | Version | Release Date |
 | :--- | :--- |
+| [5.2.3](/releases/release-5.2.3.md) | 2021-12-03 |
 | [5.3.0](/releases/release-5.3.0.md) | 2021-11-30 |
 | [5.2.2](/releases/release-5.2.2.md) | 2021-10-29 |
 | [5.1.2](/releases/release-5.1.2.md) | 2021-09-27 |