Produce a table similar to the favourability score analysis

[kauedesousa]

Work on the PlackettLuce estimates to generate a table similar to the one previous produced with the favourability scores. This table has been used in a variety release application in Tanzania and could benefit other teams.

[kauedesousa]

First progress made here by implementing the function preference_index() in the package gosset AgrDataSci/gosset@91a6874

And here 3c276ff

Next steps

• Update scripts in the Report
• Update the markdown file and add description of the table