Modernize portfolio optimizer (#376)

* added panel dashboard

* clear outputs

* added more text description to cells

* improved the introduction of the notebook

* removed param.watch

* cleared outputs

* added more cell descriptions

* fixed linter error

* updated holoview plots to hvplot

* removed outputs

* updated yml

* minor edits to made code more readable

* changes to cell descriptions

* updated yml files

* updated yaml files again

* dr revision of text code and viz

* color the distribution plots

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Co-authored-by: jtao1 <jtao@LAPTOP-UKS0PRO9>
Co-authored-by: Demetris Roumis <roumis.d@gmail.com>