feat(dev-tools): add precommit hooks for linting

add prettier for formatting control
add eslint for linting js
add husky to run hooks at precommit stage

closes: #36

.eslintrc

@@ -0,0 +1,24 @@
+{
+  "extends": ["eslint:recommended", "prettier"],
+  "env": {
+    "browser": true,
+    "node": true,
+    "es6": true,
+    "commonjs": true,
+    "es2021": true
+  },
+  "parserOptions": {
+    "ecmaVersion": 12
+  },
+  "rules": {
+    "no-unused-vars": [
+      "error",
+      {
+        "vars": "local",
+        "args": "none"
+      }
+    ],
+    "no-plusplus": "off",
+    "no-underscore-dangle": "off"
+  }
+}

.prettierrc

@@ -0,0 +1,11 @@
+{
+  "printWidth": 80,
+  "tabWidth": 2,
+  "useTabs": false,
+  "semi": true,
+  "singleQuote": true,
+  "trailingComma": "all",
+  "bracketSpacing": false,
+  "jsxBracketSameLine": false,
+  "proseWrap": "always"
+}

package.json

@@ -10,10 +10,31 @@
   "author": "Grey Software",
   "license": "MIT",
   "devDependencies": {
-    "vuepress": "^1.5.2"
+    "vuepress": "^1.5.2",
+    "eslint": "^7.9.0",
+    "eslint-config-prettier": "^6.11.0",
+    "husky": "^4.3.0",
+    "lint-staged": "^10.3.0",
+    "prettier": "^2.1.1"
   },
   "dependencies": {
     "vue-svg-loader": "^0.16.0",
     "vue-typed-js": "^0.1.2"
+  },
+  "husky": {
+    "hooks": {
+      "pre-commit": "npx lint-staged"
+    }
+  },
+  "lint-staged": {
+    "*.{json,yml}": [
+      "prettier --write",
+      "git add"
+    ],
+    "**/*.+(js|md|ts|css|sass|less|graphql|vue)": [
+      "prettier --write",
+      "eslint --fix",
+      "git add"
+    ]
   }
 }