text: Title: Cannot build a new model
  Body: When I want to contribute a new model, it notices me as:
  
  return _bootstrap._gcd_import(name[level:], package, level)
    File "<frozen importlib._bootstrap>", line 1006, in _gcd_import
    File "<frozen importlib._bootstrap>", line 983, in _find_and_load
    File "<frozen importlib._bootstrap>", line 965, in _find_and_load_unlocked
  ModuleNotFoundError: No module named 'qlib.contrib.model.pytorch_newmodel_ts'
  
  How can I solve this. & So, is there a document for development?
  