Parameter docstring does not show in --help-notebook if it contains equal sign (=)

[ivsanro1]

🐛 Bug

If I create a notebook with some parameter and a docstring to be shown by --help-notebook:

papermill --help-notebook example.ipynb 
Usage: papermill [OPTIONS] NOTEBOOK_PATH [OUTPUT_PATH]

Parameters inferred for notebook 'example.ipynb':
  alpha: float (default 0.5)      Alpha value
  n_jobs: int (default 1)         Number of workers to launch

But if the docstring of the parameter contains =, --help-notebook does not show it:

papermill --help-notebook example.ipynb 
Usage: papermill [OPTIONS] NOTEBOOK_PATH [OUTPUT_PATH]

Parameters inferred for notebook 'example.ipynb':
  alpha: float (default 0.5)      Alpha value

papermill version 2.4.0