Roxygen: update to handle updates in {purrr}

[HenrikBengtsson]

purrr has been updated such that re-roxygenizing the current version will:

1. cause some parameters to be undocumented, e.g. .id and .l
2. bring in paragraphs that are not relevant to furrr, e.g. "Wrap a function with in_parallel() to declare that it should be performed in parallel."

I think the easiest is to:

1. add the missing @inheritParams purrr::...
2. manually identify which @param:s have to be manually copied and pruned.

[HenrikBengtsson]

@DavisVaughan , is it okay if I go ahead and merge PR #286? Trying to get to an all OK on GitHub Actions for a starter.

[HenrikBengtsson]

@DavisVaughan , just a friendly reminder about this. I'd like for furrr to catch up so #282 can be added.