demonstrate interactive use
more notes about BiocCheck vs check
When checking tarball, allow vignette sources in inst/doc (demote to NOTE)

This is ok because "R CMD build" puts vignette sources in
inst/doc. It's not wrong and there's nothing the user
can do about it, but we NOTE it all the same.

However, if the user is checking a directory, not a tarball,
we make this a RECOMMENDED issue.
Merge branch 'maindev'