docs: fix heading levels (#1888)

Signed-off-by: WenyXu <[email protected]>

Author: WenyXu

docs/user-guide/deployments-administration/disaster-recovery/back-up-&-restore-meta-data.md

@@ -42,7 +42,7 @@ greptime cli meta snapshot save \
     --backend postgres-store
 ```
 
-### From MySQL Backend
+#### From MySQL Backend
 
 Export metadata from MySQL to local directory:
 
@@ -100,9 +100,9 @@ greptime cli meta snapshot restore \
     --backend postgres-store
 ```
 
-### From MySQL Backend
+#### To MySQL Backend
 
-Export metadata from MySQL to local directory:
+Restore metadata from local backup file to MySQL:
 
 ```bash
 greptime cli meta snapshot restore \

i18n/zh/docusaurus-plugin-content-docs/current/user-guide/deployments-administration/disaster-recovery/back-up-&-restore-meta-data.md

@@ -42,7 +42,7 @@ greptime cli meta snapshot save \
     --backend postgres-store
 ```
 
-### 从 MySQL 后端导出
+#### 从 MySQL 后端导出
 
 将元数据从 MySQL 导出到本地目录：
 
@@ -99,7 +99,7 @@ greptime cli meta snapshot restore \
     --backend postgres-store
 ```
 
-### 导入到 MySQL 后端
+#### 导入到 MySQL 后端
 
 从本地备份文件恢复元数据到 MySQL: