update eslint

.eslintrc.js

@@ -0,0 +1,35 @@
+module.exports = {
+    "env": {
+        "browser": true,
+        "es6": true
+    },
+    "extends": [
+        "eslint:recommended",
+        "plugin:vue/essential"
+    ],
+    "globals": {
+        "Atomics": "readonly",
+        "SharedArrayBuffer": "readonly"
+    },
+    "parserOptions": {
+        "ecmaVersion": 2018,
+        "sourceType": "module"
+    },
+    "plugins": [
+        "vue"
+    ],
+    "rules": {
+        "indent": [
+            "warn",
+            2
+        ],
+        "linebreak-style": [
+            "error",
+            "unix"
+        ],
+        "quotes": [
+            "warn",
+            "single"
+        ]
+    }
+}

package.json

@@ -18,38 +18,22 @@
     "ws": "^7.3.1"
   },
   "devDependencies": {
+    "@babel/plugin-proposal-nullish-coalescing-operator": "^7.13.0",
+    "@babel/plugin-syntax-nullish-coalescing-operator": "^7.8.3",
     "@vue/cli-plugin-babel": "~4.5.0",
     "@vue/cli-plugin-eslint": "~4.5.0",
+    "@vue/cli-plugin-pwa": "~4.5.0",
     "@vue/cli-service": "~4.5.0",
+    "@vue/compiler-sfc": "^3.0.0",
+    "babel": "^6.23.0",
+    "babel-cli": "^6.18.0",
     "babel-eslint": "^10.1.0",
     "electron": "^11.0.1",
-    "eslint": "^7.14.0",
-    "eslint-config-airbnb-base": "^14.2.1",
-    "eslint-config-standard": "^16.0.2",
-    "eslint-plugin-import": "^2.22.1",
-    "eslint-plugin-node": "^11.1.0",
-    "eslint-plugin-promise": "^4.2.1",
-    "eslint-plugin-vue": "^7.2.0",
+    "eslint": "^6.7.2",
+    "eslint-plugin-vue": "^7.5.0",
+    "node-sass": "^5.0.0",
+    "sass-loader": "^10.1.1",
     "vue-router": "^3.4.9",
     "vue-template-compiler": "^2.6.11"
-  },
-  "eslintConfig": {
-    "root": true,
-    "env": {
-      "node": true
-    },
-    "extends": [
-      "plugin:vue/essential",
-      "eslint:recommended"
-    ],
-    "parserOptions": {
-      "parser": "babel-eslint"
-    },
-    "rules": {}
-  },
-  "browserslist": [
-    "> 1%",
-    "last 2 versions",
-    "not dead"
-  ]
+  }
 }