RPYS (Reference Publication Year Spectroscopy) Plot

>>> from techminer2.packages.rpys import RPYSPlot
>>> plot = (
...     RPYSPlot()
...     #
...     # DATABASE:
...     .where_root_directory_is("example/")
...     .run()
... )
>>> # plot.write_html("docs_src/_generated/packages/rpys/rpys_plot.html")