docs: use 'pmm setting mirror ...' (mirror subcommands moved under setting)

web/docs/md/cli.md

@@ -26,11 +26,11 @@ pmm verify <file>              # sha256/sha1
 ## 镜像 / 更新
 
 ```bash
-pmm mirror list
-pmm mirror add <n> <api>
-pmm mirror use <n>
-pmm mirror remove <n>
-pmm mirror check               # 探测各镜像源可达性
+pmm setting mirror list
+pmm setting mirror add <n> <api>
+pmm setting mirror use <n>
+pmm setting mirror remove <n>
+pmm setting mirror check             # 探测各镜像源可达性
 pmm update                     # 刷新镜像索引
 pmm upgrade [--yes]            # 升级所有已装包
 pmm self-update                # 更新 pmm 自身

web/docs/md/index.md

@@ -27,7 +27,7 @@ pmm search <kw>          搜索
 pmm info <pkg>           详情
 pmm update               刷新镜像索引
 pmm upgrade              升级所有已装包
-pmm mirror list          查看镜像源
+pmm setting mirror list  查看镜像源
 pmm setting lang <xx>    切换语言包
 ```
 

web/docs/md/mirror.md

@@ -23,11 +23,11 @@ priority = 20
 ## 管理镜像
 
 ```bash
-pmm mirror list          # 列出
-pmm mirror add <n> <api> # 添加
-pmm mirror use <n>       # 设为当前
-pmm mirror remove <n>    # 移除
-pmm mirror check         # 探测每个源的可达性/优先级
+pmm setting mirror list          # 列出
+pmm setting mirror add <n> <api> # 添加
+pmm setting mirror use <n>       # 设为当前
+pmm setting mirror remove <n>    # 移除
+pmm setting mirror check         # 探测每个源的可达性/优先级
 ```
 
 ## 服务状态