Add OBB Counting example in Docs (#16485)

Co-authored-by: UltralyticsAssistant <web@ultralytics.com>

docs/en/guides/object-counting.md

@@ -90,6 +90,46 @@ Object counting with [Ultralytics YOLOv8](https://github.com/ultralytics/ultraly
         cv2.destroyAllWindows()
         ```
 
+    === "OBB Object Counting"
+
+        ```python
+        import cv2
+
+        from ultralytics import YOLO, solutions
+
+        model = YOLO("yolov8n-obb.pt")
+        cap = cv2.VideoCapture("path/to/video/file.mp4")
+        assert cap.isOpened(), "Error reading video file"
+        w, h, fps = (int(cap.get(x)) for x in (cv2.CAP_PROP_FRAME_WIDTH, cv2.CAP_PROP_FRAME_HEIGHT, cv2.CAP_PROP_FPS))
+
+        # Define region points
+        region_points = [(20, 400), (1080, 404), (1080, 360), (20, 360)]
+
+        # Video writer
+        video_writer = cv2.VideoWriter("object_counting_output.avi", cv2.VideoWriter_fourcc(*"mp4v"), fps, (w, h))
+
+        # Init Object Counter
+        counter = solutions.ObjectCounter(
+            view_img=True,
+            reg_pts=region_points,
+            names=model.names,
+            line_thickness=2,
+        )
+
+        while cap.isOpened():
+            success, im0 = cap.read()
+            if not success:
+                print("Video frame is empty or video processing has been successfully completed.")
+                break
+            tracks = model.track(im0, persist=True, show=False)
+            im0 = counter.start_counting(im0, tracks)
+            video_writer.write(im0)
+
+        cap.release()
+        video_writer.release()
+        cv2.destroyAllWindows()
+        ```
+
     === "Count in Polygon"
 
         ```python
@@ -123,7 +163,6 @@ Object counting with [Ultralytics YOLOv8](https://github.com/ultralytics/ultraly
                 print("Video frame is empty or video processing has been successfully completed.")
                 break
             tracks = model.track(im0, persist=True, show=False)
-
             im0 = counter.start_counting(im0, tracks)
             video_writer.write(im0)
 
@@ -165,7 +204,6 @@ Object counting with [Ultralytics YOLOv8](https://github.com/ultralytics/ultraly
                 print("Video frame is empty or video processing has been successfully completed.")
                 break
             tracks = model.track(im0, persist=True, show=False)
-
             im0 = counter.start_counting(im0, tracks)
             video_writer.write(im0)
 
@@ -207,7 +245,6 @@ Object counting with [Ultralytics YOLOv8](https://github.com/ultralytics/ultraly
                 print("Video frame is empty or video processing has been successfully completed.")
                 break
             tracks = model.track(im0, persist=True, show=False, classes=classes_to_count)
-
             im0 = counter.start_counting(im0, tracks)
             video_writer.write(im0)