Add advice for text + line + col + file hyperlink

[olivroy]

Until #601 is fixed.

I tried looking into fixing it, but couldn't figure it out due to the regexp.

I added this clarification about line and col being numeric, because I was once extracting regexp and forgot to convert to numeric, and they get ignored.

# silently fails
cli::style_hyperlink(
  text = "R profile at line 5",
  url = "file://~/.Rprofile",
  params = c(line = "5", col = "1")
)

Edit 2: from posit-dev/positron#4968 (reply in thread) it is also better to use absolute paths as opposed to relative paths for this syntax

[olivroy]

@gaborcsardi It seems that this syntax doesn't work in Positron? Should an issue be open there, or is that something that can be fixed with cli?

edit: Apparently, this is a newly introduced Positron bug. posit-dev/positron#4968

I changed list() to c() like it is in warn_roxy()

https://github.com/r-lib/roxygen2/blob/9652d15221109917d46768e836eaf55e33c21633/R/utils-warn.R#L24-L34

It seems that this works correctly in Positron