docs: document ROS2 IMU rate aliases

docs/en/source/camera_devices/4_application_guide/launch_parameters.md

@@ -376,7 +376,7 @@ The following are the launch parameters available:
 *   **`enable_sync_output_accel_gyro`**
     *   Enable the sync `accel_gyro`, and output IMU topic real-time data.
 *   **`accel_rate`** / **`gyro_rate`**
-    *   The frequency of the accelerometer/gyroscope. Values range from `1.5625hz` to `32khz`.
+    *   The frequency of the accelerometer/gyroscope. Values range from `1.5625hz` to `32khz`. High-rate aliases such as `1000hz`, `2000hz`, `4000hz`, `8000hz`, `16000hz`, and `32000hz` are also accepted; the equivalent `1khz`–`32khz` forms remain supported.
 *   **`accel_range`** / **`gyro_range`**
     *   The range of the accelerometer (`2g`, `4g`, `8g`, `16g`) and gyroscope (`16dps` to `2000dps`).
 *   **`enable_accel_data_correction`** / **`enable_gyro_data_correction`**

docs/zh/source/camera_devices/4_application_guide/launch_parameters.md

@@ -375,7 +375,7 @@
 *   **`enable_sync_output_accel_gyro`**
     *   启用同步 `accel_gyro`，并输出IMU话题实时数据。
 *   **`accel_rate`** / **`gyro_rate`**
-    *   加速度计/陀螺仪的频率。值范围从 `1.5625hz` 到 `32khz`。
+    *   加速度计/陀螺仪的频率。值范围从 `1.5625hz` 到 `32khz`。高采样率也支持 `1000hz`、`2000hz`、`4000hz`、`8000hz`、`16000hz` 和 `32000hz` 写法；等价的 `1khz`～`32khz` 写法仍然支持。
 *   **`accel_range`** / **`gyro_range`**
     *   加速度计（`2g`、`4g`、`8g`、`16g`）和陀螺仪（`16dps` 到 `2000dps`）的范围。
 *   **`enable_accel_data_correction`** / **`enable_gyro_data_correction`**