message: Added note about implementing features by outside contributors
diff: @@ -23,6 +23,7 @@ When logging a bug, please be sure to include the following:
  ## Pull Requests
  +- Outside contributors may implement enhancement/features only _after an approval_ (label "help wanted") by Lightweight Charts project maintainers.
  - For build instructions/suggestions see [BUILDING.md](./BUILDING.md).
  - After the review process has started, please **don't** use rebase to update the branch, use merge instead.
  