Update to roxygen2 @template for ggplot2_args arguments

[averissimo]

Pull Request

• Closes [Docs] Update ggplot2_args roxygen2 template or integrate with shared_params #695
• Part of Pre-release activities #624

Changes description

• Update type in ggplot2_args
• Minor change to phrasing
• Move template file under man page to avoid extra folder at root level (available since [email protected])
• Update .Rbuildignore accordingly

Reviewer should consider

• @template has been superseded (https://roxygen2.r-lib.org/articles/reuse.html?q=template#superseded)
  • There's no equivalent though (with parameterized strings)
  • Alternative: we could add ggplot2_args to shared_params and specific list of names it can take in @details on each function that uses this

[averissimo]

R CMD check, {lintr} and {styler} pass

[gogonzo]

👍