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 = list(line = "5", col = "1")
)