message: Describe speedy testing workflow in CONTRIBUTING.md
diff: @@ -61,6 +61,10 @@ You can test your change by using the automated tests packaged with PixiJS. You
  by running `npm test` from the command line. If you fix a bug please add a test that will catch that
  bug if it ever happens again. This prevents regressions from sneaking in.
  +For a speedy workflow:
  +1. Run `npm start` in one terminal. This watches the source tree and compiles it incrementally.
  +2. When desired, run `npm run unit-test` in another terminal. This runs tests using the compilation output from `npm start`.
  +
  ### Submitting Your Change
  After you have made and tested your change, commit and push it to your fork. Then, open a Pull Request
  