Add `export.py` ONNX inference suggestion
diff --git a/export.py b/export.py
index ceee15e1644..c98e92d972c 100644
--- a/export.py
+++ b/export.py
@@ -76,6 +76,7 @@ def export_onnx(model, img, file, opset, train, dynamic, simplify):
             except Exception as e:
                 print(f'{prefix} simplifier failure: {e}')
         print(f'{prefix} export success, saved as {f} ({file_size(f):.1f} MB)')
+        print(f"{prefix} run --dynamic ONNX model inference with detect.py: 'python detect.py --weights {f}'")
     except Exception as e:
         print(f'{prefix} export failure: {e}')
 
@@ -94,7 +95,7 @@ def export_coreml(model, img, file):
         model.save(f)
         print(f'{prefix} export success, saved as {f} ({file_size(f):.1f} MB)')
     except Exception as e:
-        print(f'{prefix} export failure: {e}')
+        print(f'\n{prefix} export failure: {e}')
 
 
 def run(weights='./yolov5s.pt',  # weights path



## 🛠️ PR Summary

<sub>Made with ❤️ by [Ultralytics Actions](https://github.com/ultralytics/actions)<sub>

### 🌟 Summary
Improvements to model export feedback in the Ultralytics YOLOv5 repository.

### 📊 Key Changes
- Added additional output message guiding users on how to run ONNX model inference after successful export.
- Improved error visibility in export failure by adding a line break before the error message.

### 🎯 Purpose & Impact
- The new output message provides clear instructions for using the exported ONNX model, making it easier for users to understand the next steps. 🧭
- Formatting the error message with a preceding line break increases its visibility, helping users to quickly identify export issues. 🚨

This PR enhances user experience by streamlining the process and guidance provided after model export, leading to a more intuitive workflow for YOLOv5 users.