Add section organization to 14_benchmarking module: Add DEVELOPMENT section header

- Insert ## 🔧 DEVELOPMENT header before first test function
- Organizes module according to educational structure guidelines
- Maintains all existing functionality and test execution
- Improves readability and navigation for educational use

modules/source/14_benchmarking/benchmarking_dev.py

@@ -448,6 +448,8 @@ class BenchmarkScenarios:
 
 # %% [markdown]
 """
+## 🔧 DEVELOPMENT
+
 ### 🧪 Unit Test: Benchmark Scenarios
 
 Let's test our benchmark scenarios with a simple mock model.