message: Add documentation about the --silent npm command option
diff: @@ -32,6 +32,8 @@ The source code is organized according to where it can run:
  4. Build source: `npm run build`
  5. Run tests: `npm test`
  +If you want less verbose clean and build commands, please use the `-s` or `--silent` option. For example: `npm run clean -s`
  +
  Note that all build instructions are designed to run from the imodeljs-core root directory.
  The individual commands orchestrate separate backend, frontend, and test steps as required.
  