R: support highlight for different R-related files

[kevinushey]

For example:

• DESCRIPTION
• NAMESPACE
• *.Rd
• renv.lock

Do we need to think about highlight rules for R Markdown documents? Or will we lean on the Quarto extension for that?

[jennybc]

DESCRIPTION (and other Debian control files) was addressed in #1140

[hadley]

NAMESPACE is just regular R syntax so should be easy.

I don't think many people look at .Rd files directly, but some minimal highlighting for structure would be useful.

[jennybc]

I think this is done.

[jennybc]

Oops I should not close before #1479 gets merged.

[lionel-]

NAMESPACE, DESCRIPTION, and .Rd files now look great!

[lionel-]

A nice improvement for non-users of roxygen2 would be to let Cmd+Enter execute lines of code in the example field.

Screen.Recording.2023-10-05.at.10.48.27.mov

Should I open an issue about this?

[jennybc]

You could maybe add to #1410.