message: Update CONTRIBUTING.md guidelines
diff: # Contributing
  -Contributions to `react-querybuilder` are more than welcome. When doing so, please first discuss the change you wish to make via an issue.
  +Contributions to `react-querybuilder` are more than welcome. When preparing to submit a pull request, please first discuss the change you wish to make by creating a [new issue](/react-querybuilder/react-querybuilder/issues/new) or [discussion topic](/react-querybuilder/react-querybuilder/discussions/new).
  -- If adding a new feature, write the corresponding tests
  -- Ensure that your work didn't break anything
  -- If applicable, update the readme
  -- If applicable, update the typescript definition
  -- Use prettier before commiting (the config is in root)
  -- When solving a bug, please provide the steps to reproduce it (codesandbox is great)
  +- If adding a new feature, be sure to add corresponding tests (we maintain 100% coverage).
  +- Ensure that your work didn't break anything.
  +- If changing behavior or adding a feature, update the [documentation site](/react-querybuilder/react-querybuilder.github.io/).
  +- If applicable, update the TypeScript definitions.
  +- Run `yarn pretty-print` (which runs prettier) before committing.
  +- When solving a bug, please provide the steps to reproduce it (CodeSandbox is great -- feel free to fork our [CI base](https://codesandbox.io/s/oq8ts) to get started).
  