Add eslint configuration with precommit npm hook

.eslintrc.json

@@ -0,0 +1,32 @@
+{
+  "env": {
+    "es6": true,
+    "node": true
+  },
+  "extends": ["airbnb-base"],
+  "globals": {
+    "Atomics": "readonly",
+    "SharedArrayBuffer": "readonly"
+  },
+  "parser": "@typescript-eslint/parser",
+  "parserOptions": {
+    "ecmaVersion": 2018,
+    "sourceType": "module"
+  },
+  "plugins": ["@typescript-eslint"],
+  "rules": {
+    "arrow-body-style": 0,
+    "arrow-parens": [2, "as-needed", { "requireForBlockBody": true }],
+    "comma-dangle": [2, "always-multiline"],
+    "import/prefer-default-export": 0,
+    "max-len": ["error", {
+      "code": 120,
+      "comments": 120,
+      "ignoreComments": false,
+      "tabWidth": 2
+    }],
+    "no-confusing-arrow": 0,
+    "no-underscore-dangle": ["error", { "allow": ["__typename"] }],
+    "semi": [2, "never"]
+  }
+}