holoviz/hvplot

AI Summary: Add `versionadded` admonitions to the docstrings of the `backend_opts`, `legend_cols`, `legend_opts`, `toolbar`, and `autohide_toolbar` keywords in the hvPlot documentation to indicate their introduction in version 0.12.

AI Summary: Investigate why the 'alpha' keyword argument is not affecting the transparency of parallel coordinates plots generated by hvPlot. Debugging will likely involve inspecting the code that handles parallel coordinate plot generation and how alpha values are applied within the chosen plotting backend (Bokeh, Matplotlib, or Plotly). A solution might involve modifying the hvPlot code to correctly pass the alpha value to the backend or identifying a configuration issue.