docs: fix sync description

docs/en/guide/sync.md

@@ -25,15 +25,15 @@ juicefs sync s3://mybucket.s3.us-east-2.amazonaws.com/ jfs://VOL_NAME/
 juicefs sync --match-full-path --include='**.gz' --exclude='*' s3://xxx jfs://VOL_NAME/
 
 # Copy all files that do not end with .gz
-juicefs sync --match-full-path --exclude='**.gz' --include='*' s3://xxx/ jfs://VOL_NAME/
+juicefs sync --match-full-path --exclude='**.gz' s3://xxx/ jfs://VOL_NAME/
 
 # Copy all files except the subdirectory named tempdir
-juicefs sync --match-full-path --include='*' --exclude='**/tmpdir/**' s3://xxx/ jfs://VOL_NAME/
+juicefs sync --match-full-path --include='*' s3://xxx/ jfs://VOL_NAME/
 ```
 
 ## Pattern matching {#pattern-matching}
 
-You can use `--exclude` and `--include` for filtering. If no filtering rules are provided, all files are scanned and copied. However, if you do need filtering, you must use both `--include` and `--exclude` for any of them to work properly (see examples above for reference).
+You can use `--exclude` and `--include` for filtering. If no filtering rules are provided, all files are scanned and copied (`--include='*'` is the default). However, if you were to use `--include` filter to only handle files with the specified pattern, then you must also use `--exclude` as well, see examples above for reference.
 
 :::tip
 When using multiple matching patterns, it may be difficult to determine whether a file will be synchronized due to the filtering logic. In such cases, it is recommended to add the `--dry --debug` option to preview the files selected for synchronization. If the results are not as expected, adjust the matching patterns accordingly.
@@ -57,10 +57,6 @@ In addition:
 
 Here are some examples of matching patterns:
 
-:::tip
-`--include` and `--exclude` must **be used together**. If you only specify `--include` without any `--exclude`, filtering will not work (and vice versa). Therefore, if you want to copy a command from examples below, ensure you append `--include='*'` to make them effective.
-:::
-
 + `--exclude='*.o'` excludes all files matching `*.o`.
 + `--exclude='/foo/*/bar'` excludes `bar` files located two levels under `/foo`, such as `/foo/spam/bar`, but not `/foo/spam/eggs/bar`.
 + `--exclude='/foo/**/bar'` excludes `bar` files at any level under `/foo`.

docs/zh_cn/guide/sync.md

@@ -22,15 +22,15 @@ juicefs sync oss://mybucket.oss-cn-shanghai.aliyuncs.com s3://mybucket.s3.us-eas
 juicefs sync --match-full-path --include='**.gz' --exclude='*' s3://xxx s3://xxx
 
 # 拷贝不以 .gz 结尾的所有文件
-juicefs sync --match-full-path --exclude='**.gz' --include='*' s3://xxx/ s3://xxx
+juicefs sync --match-full-path --exclude='**.gz' s3://xxx/ s3://xxx
 
 # 拷贝所有文件，但忽略名为 tmpdir 的子目录
-juicefs sync --match-full-path --include='*' --exclude='**/tmpdir/**' s3://xxx/ s3://xxx
+juicefs sync --match-full-path --exclude='**/tmpdir/**' s3://xxx/ s3://xxx
 ```
 
 ## 模式匹配 {#pattern-matching}
 
-你可以通过 `--exclude` 和 `--include` 来包含或排除要同步的文件路径。如果不提供任何规则，默认会同步所有扫描到的文件。但如果需要过滤特定文件，则**必须同时使用`--include` 和 `--exclude`**，不可以单独只使用其一，具体请参考上方的示范命令。
+你可以通过 `--exclude` 和 `--include` 来包含或排除要同步的文件路径。如果不提供任何规则，默认会同步所有扫描到的文件（默认就是 `--include='*'`）。但如果需要使用 `--include` 实现只包含特定命名模式的文件，则**必须同时使用 `--exclude` 来排除其他文件**，具体请参考上方的示范命令。
 
 :::tip
 当提供多个匹配模式时，取决于你具体使用的「过滤模式」，对于判断是否要同步某个文件可能会变得很困难。此时建议加上 `--dry --debug` 选项提前查看要同步的具体文件是否符合预期，如果不符合预期则需要调整匹配模式。
@@ -54,10 +54,6 @@ juicefs sync --match-full-path --include='*' --exclude='**/tmpdir/**' s3://xxx/
 
 以下是一些匹配模式的例子：
 
-:::tip
-`--include` 和 `--exclude` 必须**同时使用**，不能只用 `--include` 而没有 `--exclude`，反之亦然。因此如果要仿照下方示范撰写命令，还需要额外追加 `--include='*'` 才能发挥作用。
-:::
-
 + `--exclude '*.o'` 将排除所有文件名能匹配 `*.o` 的文件；
 + `--exclude '/foo/*/bar'` 将排除根目录中名为 `foo` 的目录向下「两层」的目录中名为 `bar` 的文件；
 + `--exclude '/foo/**/bar'` 将排除根目录中名为 `foo` 的目录向下「任意层级」的目录中名为 `bar` 的文件。