docs: document ROS2 depth colorizer modes

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

@@ -361,6 +361,9 @@ The following are the launch parameters available:
     *   This parameter is case-insensitive. Use one of the valid values listed above.
 *   **`enable_d2c_viewer`**
     *   Publishes the D2C overlay image (for testing only). See [Aligning Depth to Color](../5_advanced_guide/configuration/align_depth_color.md) for examples.
+*   **`depth_colorizer_mode`**
+    *   Colorizes the depth image published on `/camera/depth/image_raw`. Supported values are `none`, `jet`, `jet_inv`, and `gray`. `none` keeps the raw depth image, `gray` publishes `mono8`, and `jet` / `jet_inv` publish `rgb8`.
+    *   When a colorizer mode other than `none` is selected together with `enable_d2c_viewer:=true`, the node logs a warning and automatically disables `enable_d2c_viewer`, because the viewer requires a raw `16UC1` depth image.
 
 ## IMU
 

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

@@ -19,6 +19,7 @@ These topics provide the raw image data and corresponding calibration informatio
 
 *   `/camera/depth/image_raw`
     *   Raw image data from the depth stream.
+    *   When `depth_colorizer_mode` is `none`, the topic keeps the raw depth encoding. `gray` changes the published encoding to `mono8`; `jet` and `jet_inv` change it to `rgb8`.
 *   `/camera/depth/camera_info`
     *   Camera calibration data and metadata for the depth stream.
 *   `/camera/depth/metadata`