Fix filename for label in CamVid format (cvat-ai#6600)

Fixed the filename for the label map file in CamVid format from 'labelmap.txt' to 'label_colors.txt'

CHANGELOG.md

@@ -39,6 +39,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Accidentally using prebuilt FFmpeg bundled in PyAV instead of the custom
   build.
+- Fix filename for label in CamVid format (<https://github.com/opencv/cvat/pull/6600>)
 
 ### Security
 

site/content/en/docs/manual/advanced/formats/format-camvid.md

@@ -13,7 +13,7 @@ Downloaded file: a zip archive of the following structure:
 
 ```bash
 taskname.zip/
-├── labelmap.txt # optional, required for non-CamVid labels
+├── label_colors.txt # optional, required for non-CamVid labels
 ├── <any_subset_name>/
 |   ├── image1.png
 |   └── image2.png
@@ -22,13 +22,23 @@ taskname.zip/
 |   └── image2.png
 └── <any_subset_name>.txt
 
-# labelmap.txt
+# label_colors.txt (with color value type)
+# if you want to manually set the color for labels, configure label_colors.txt as follows:
 # color (RGB) label
 0 0 0 Void
 64 128 64 Animal
 192 0 128 Archway
 0 128 192 Bicyclist
 0 128 64 Bridge
+
+# label_colors.txt (without color value type)
+# if you do not manually set the color for labels, it will be set automatically:
+# label
+Void
+Animal
+Archway
+Bicyclist
+Bridge
 ```
 
 Mask is a `png` image with 1 or 3 channels where each pixel