message: add prettier to package.json lint commands
  ## Description
  This PR adds prettier to our lint scripts in
  `packages/dds/tree/package.json`, to enforce prettier. The `lint:fix`
  script also was run afterwards.
  This PR is a portion of as it was suggested that the prettier
  should be run in several PRs.
diff: "eslint:fix": "eslint --format stylish src --fix --fix-type problem,suggestion,layout",
  "fence": "gf",
  "format": "npm run prettier:fix",
  - "lint": "npm run eslint",
  - "lint:fix": "npm run eslint:fix",
  + "lint": "npm run prettier && npm run eslint",
  + "lint:fix": "npm run prettier:fix && npm run eslint:fix",
  + "prettier": "prettier --check . --ignore-path ../../../.prettierignore",
  "prettier:fix": "prettier --write . --ignore-path ../../../.prettierignore",
  "test": "npm run test:mocha",
  "test:benchmark:report": "mocha \"dist/**/*.bench.js\" --node-option unhandled-rejections=strict,expose-gc --exit --perfMode --fgrep @Benchmark -r @fluidframework/mocha-test-setup --reporter @fluid-tools/benchmark/dist/MochaReporter.js --timeout 60000",
  