chore: use lint-staged for JS pre-commit linting (#436)

xwd-dev-lib lints in a tmp dir with changed files only, which makes
import/no-unresolved rule fail at times, as not all files are present

composer.json

@@ -28,7 +28,7 @@
 	},
 	"extra": {
 		"hooks": {
-			"pre-commit": "./vendor/xwp/wp-dev-lib/scripts/pre-commit && ./node_modules/.bin/lint-staged",
+			"pre-commit": "DEV_LIB_SKIP=eslint ./vendor/xwp/wp-dev-lib/scripts/pre-commit && ./node_modules/.bin/lint-staged",
 			"commit-msg": [
 				"cat $1 | ./node_modules/.bin/commitlint"
 			]

package.json

@@ -77,6 +77,9 @@
   "browserslist": [
     "extends @wordpress/browserslist-config"
   ],
+  "lint-staged": {
+    "*.scss": "npm run lint:scss:staged"
+  },
   "jest": {
     "setupFilesAfterEnv": [
       "<rootDir>/assets/setupTests.js"
@@ -109,16 +112,14 @@
     "test": "jest",
     "lint": "npm-run-all --parallel lint:*",
     "lint:js": "eslint --ext .js,.jsx assets",
+    "lint:js:staged": "eslint --ext .js,.jsx",
     "format:js": "prettier 'assets/**/*.{js,jsx}' --write",
     "lint:scss": "stylelint '**/*.scss' --syntax scss",
     "format:scss": "prettier --write '**/*.scss'",
     "lint:scss:staged": "stylelint --syntax scss",
     "release:archive": "mkdir -p assets/release && zip -r assets/release/newspack-plugin.zip . -x node_modules/\\* .git/\\* .github/\\* .gitignore .DS_Store tests/\\* assets/\\* vendor/\\*",
     "release": "run-p \"build\" && run-p \"release:archive\""
   },
-  "lint-staged": {
-    "*.scss": "npm run lint:scss:staged"
-  },
   "dependencies": {
     "@material-ui/core": "^4.8.2",
     "@material-ui/icons": "^4.5.1",