docs: ✏️ Update docs for yarn scripts (#1101)

addons/api/package.json

@@ -16,11 +16,12 @@
     "lint:hbs:fix": "ember-template-lint . --fix",
     "lint:js": "eslint .",
     "lint:js:fix": "eslint . --fix",
-    "format": "npm run format:js",
+    "format": "yarn run format:js",
     "format:js": "prettier --write '{addon,app,config,stories,tests,mirage}/**/*.js' *.js",
     "start": "ember serve",
     "test": "ember test",
     "test:ember-compatibility": "ember try:each",
+    "precommit": "yarn lint && yarn format && yarn test",
     "doc:toc": "doctoc README.md"
   },
   "dependencies": {