fix linting playground sources does not work on Windows

Author: rhysd

playground/.prettierrc.json

@@ -5,6 +5,7 @@
   "trailingComma": "es5",
   "printWidth": 120,
   "arrowParens": "avoid",
+  "endOfLine": "auto",
   "overrides": [
     {
       "files": "*.css",

playground/package.json

@@ -6,11 +6,11 @@
   "main": "main.js",
   "scripts": {
     "lint:stylelint": "stylelint style.css",
-    "lint:prettier": "prettier --check '*.ts' '*.mjs'",
-    "lint:eslint": "eslint --max-warnings 0 '*.ts' '*.mjs'",
+    "lint:prettier": "prettier --check *.ts *.mjs",
+    "lint:eslint": "eslint --max-warnings 0 *.ts *.mjs",
     "lint:tsc-eslint": "tsc -p tsconfig.eslint.json",
     "lint": "npm run lint:prettier && npm run lint:eslint && npm run lint:stylelint && npm run lint:tsc-eslint",
-    "prettier": "prettier --write '*.ts' '*.mjs'",
+    "prettier": "prettier --write *.ts *.mjs",
     "build": "tsc -p .",
     "watch": "tsc -p . --watch",
     "serve": "http-server . -p 1234",