[ADD] cfworker eslint

cf-worker/.eslintrc.json

@@ -0,0 +1,22 @@
+{
+  "env": {
+    "browser": true,
+    "es6": true
+  },
+  "extends": "eslint:recommended",
+  "globals": {
+    "Atomics": "readonly",
+    "SharedArrayBuffer": "readonly"
+  },
+  "parserOptions": {
+    "ecmaVersion": 2017,
+    "sourceType": "module"
+  },
+  "rules": {
+    "no-console": "warn",
+    "no-empty": "warn",
+    "no-unused-vars": "warn",
+    "no-debugger": "warn",
+    "no-constant-condition": "warn"
+  }
+}