chore: added desc for the mount_source/point and file_dir columns

Author: lzf575

server/querier/db_descriptions/clickhouse/tag/event/file_event.ch

@@ -55,9 +55,9 @@ vtap                       , 采集器                     , 已废弃，请使
 agent                      , 采集器                     ,
 signal_source              , 信号源                     ,
 
-mount_source               , 挂载源                     ,
-mount_point                , 挂载点                     ,
-file_dir                   , 文件夹                     ,
+mount_source               , 挂载源                     , 目录挂载源，例如：`/dev/sda1` 表示块设备，`proc` 等（其他如 `sysfs`，`tmpfs`）表示虚拟文件系统，`10.1.2.3:/path` 表示 NFS 文件系统，`/var/lib/docker/...` 或 `overlay` 表示容器内目录的挂载源。
+mount_point                , 挂载点                     , 目录挂载点，当进程访问其他命名空间（`nsid`）下的文件时，显示为 `$nsid:/$mount_point`。
+file_dir                   , 文件夹                     , 目录，当进程访问其他命名空间（`nsid`）下的文件时，显示为 `$nsid:/$file_dir`。
 file_name                  , 文件名                     ,
 file_type                  , 文件类型                   ,
 offset                     , 偏移量                     ,

server/querier/db_descriptions/clickhouse/tag/event/file_event.en

@@ -55,9 +55,9 @@ vtap                  , DeepFlow Agent               , Deprecated，please use a
 agent                 , DeepFlow Agent               ,
 signal_source         , Signal Source                ,
 
-mount_source          , Mount Source                 ,
-mount_point           , Mount Point                  ,
-file_dir              , File Dir                     ,
+mount_source          , Mount Source                 , Mount source: for example, `/dev/sda1` represents a block device, `proc` (and others such as `sysfs`, `tmpfs`) represent virtual file systems, `10.1.2.3:/path` represents an NFS file system, `/var/lib/docker/...` or `overlay` represents the mount source of a directory inside a container.
+mount_point           , Mount Point                  , Mount point: when a process accesses files in another namespace (`nsid`), it is displayed as `$nsid:/$mount_point`.
+file_dir              , File Dir                     , Directory: when a process accesses files in another namespace (`nsid`), it is displayed as `$nsid:/$file_dir`.
 file_name             , File Name                    ,
 file_type             , File Type                    ,
 offset                , Offset                       ,