Update detection_rate description

README.md

@@ -130,7 +130,7 @@ SEA-AI/horizon-metrics provides the following performance metrics for horizon pr
 - **max_midpoint_error_px**: Indicates the maximum difference in midpoint position between the predicted and ground truth horizon, measured in pixels.
 - **num_slope_error_jumps**: Calculates the differences between errors in successive frames for the slope. It then counts the number of jumps in these errors by comparing the absolute differences to a specified threshold.
 - **num_midpoint_error_jumps**: Calculates the differences between errors in successive frames for the midpoint. It then counts the number of jumps in these errors by comparing the absolute differences to a specified threshold.
-- **detection_rate**: Measures the proportion of frames in which the horizon is successfully detected out of the total number of frames.
+- **detection_rate**: Measures the proportion of frames in which the horizon is successfully detected out of the total number of frames. Note that this does not take into account if the detected horizon is a good match with the ground_truth horizon.
 
 ## Further References