Adding an example usage to documentation

[matt-graham]

Raising as part of JOSS review openjournals/joss-reviews/issues/6713

It would help users to have one or more example sin the documentation (or top-level README) of using simdec to compute sensitivity indices / visualize the results. This could potentially use the same data already used in the tests.

[tupui]

Closing in favour of #34

[matt-graham]

Just to note that having an example usage in the documentation (not the JOSS paper) is a specific requirement JOSS reviewers are asked to check in their checklist

Example usage: Do the authors include examples of how to use the software (ideally to solve real-world analysis problems).

If the intention of closing this in favour of #34 is that you'll still include an example usage in the documentation (of reproducing the figure from JOSS paper) that's fine but otherwise I would say this should be reopened.