edits to workshop materials

[papsti]

this PR is meant for small changes to workshop materials that come up as we work through them as a group today!

please do not consider incorporating it until end of day 2025-03-20

[papsti]

one of the edits relates to installation. this is a fix that seems to only have been required for someone working in an renv environment on a linux server (me :))

another thing people came across is that install.packages(DEoptim) was required to run the sample code at the bottom of the technical preparation. this bit probably requires a fix to package dependencies, as opposed to installation instructions.

[papsti]

another note: the requirement to install.packages("DEoptim") seems to have been introduced between macpan2@v1.15.3 and macpan2@v1.16.3

[bbolker]

I don't what our general policy on dependencies is, but unless a package is critical it would be best if we could include it as Suggests: rather than Imports:

[papsti]

it would be great to have a top-level graphic/map of all the different types of macpan objects (model specification, simulator, calibrator, etc) and which functions get used to convert one type of object to the other + the types of outputs you can get from each (e.g. represented with plots)