[Docs] Fix the DanceTrack dataset annotation converting script (#827)

* Update dataset.md

* Update dataset.md

Author: yangchris11

docs/en/dataset.md

@@ -237,7 +237,7 @@ python ./tools/convert_datasets/mot/mot2coco.py -i ./data/MOT17/ -o ./data/MOT17
 python ./tools/convert_datasets/mot/mot2reid.py -i ./data/MOT17/ -o ./data/MOT17/reid --val-split 0.2 --vis-threshold 0.3
 
 # DanceTrack
-python ./tools/convert_datasets/dancetrack/dancetrack2coco.py -i ./data/DanceTrack ./data/DanceTrack/annotations
+python ./tools/convert_datasets/dancetrack/dancetrack2coco.py -i ./data/DanceTrack -o ./data/DanceTrack/annotations
 
 # CrowdHuman
 python ./tools/convert_datasets/mot/crowdhuman2coco.py -i ./data/crowdhuman -o ./data/crowdhuman/annotations

docs/zh_cn/dataset.md

@@ -238,7 +238,7 @@ python ./tools/convert_datasets/mot/mot2coco.py -i ./data/MOT17/ -o ./data/MOT17
 python ./tools/convert_datasets/mot/mot2reid.py -i ./data/MOT17/ -o ./data/MOT17/reid --val-split 0.2 --vis-threshold 0.3
 
 # DanceTrack
-python ./tools/convert_datasets/dancetrack/dancetrack2coco.py -i ./data/DanceTrack ./data/DanceTrack/annotations
+python ./tools/convert_datasets/dancetrack/dancetrack2coco.py -i ./data/DanceTrack -o ./data/DanceTrack/annotations
 
 # CrowdHuman
 python ./tools/convert_datasets/mot/crowdhuman2coco.py -i ./data/crowdhuman -o ./data/crowdhuman/annotations