message: Add actionable help message for --features
  Fix
diff: @@ -308,7 +308,8 @@ pub trait ArgMatchesExt {
  if self._is_present(flag) {
  bail!(
  "--{} is not allowed in the root of a virtual workspace\n\
  - note: while this was previously accepted, it didn't actually do anything",
  + note: while this was previously accepted, it didn't actually do anything\n\
  + help: try cd into the package and run cargo command",
  flag
  );
  }
  