Refactor path way

[vktrbr]

Change path

1. Change the path so that the streamlit application works from the optimization_ml/Regression directory
   

   optimization_ml/Regression/streamlit_app.py

   Line 5 in fbb4fcc

   sys.path.insert(0, os.path.abspath('.'))

2. Move the pink theme .streamlit to the optimization_ml/Regression directory
3. Change color for MDOpt
   The main purpose is to create streaming applications with different colors from the same repository