add prettier

package.json

@@ -80,6 +80,7 @@
     "mini-css-extract-plugin": "^0.9.0",
     "optimize-css-assets-webpack-plugin": "^5.0.3",
     "postcss-loader": "^3.0.0",
+    "prettier": "^2.0.1",
     "sass": "^1.25.0",
     "sass-loader": "^8.0.2",
     "style-loader": "^1.1.2",
@@ -111,7 +112,6 @@
     "semi": false,
     "singleQuote": true,
     "trailingComma": "all",
-    "arrowParens": "avoid",
     "tabWidth": 2
   },
   "eslintConfig": {

yarn.lock

@@ -8221,6 +8221,11 @@ prettier@^1.18.2:
   resolved "https://registry.yarnpkg.com/prettier/-/prettier-1.19.1.tgz#f7d7f5ff8a9cd872a7be4ca142095956a60797cb"
   integrity sha512-s7PoyDv/II1ObgQunCbB9PdLmUcBZcnWOcxDh7O0N/UwDEsHyqkW+Qh28jW+mVuCdx7gLB0BotYI1Y6uI9iyew==
 
+prettier@^2.0.1:
+  version "2.0.1"
+  resolved "https://registry.yarnpkg.com/prettier/-/prettier-2.0.1.tgz#3f00ac71263be34684b2b2c8d7e7f63737592dac"
+  integrity sha512-piXGBcY1zoFOG0MvHpNE5reAGseLmaCRifQ/fmfF49BcYkInEs/naD/unxGNAeOKFA5+JxVrPyMvMlpzcd20UA==
+
 pretty-format@^22.4.3:
   version "22.4.3"
   resolved "https://registry.yarnpkg.com/pretty-format/-/pretty-format-22.4.3.tgz#f873d780839a9c02e9664c8a082e9ee79eaac16f"