Add prettier

Author: konrad-szychowiak

prettier.config.js

@@ -0,0 +1,23 @@
+module.exports = {
+  printWidth: 100, // https://github.com/airbnb/javascript#19.13
+  tabWidth: 2, // https://github.com/airbnb/javascript#19.1
+  useTabs: false, // https://github.com/airbnb/javascript#19.1
+  semi: true, // https://github.com/airbnb/javascript#21.1
+  singleQuote: true, // https://github.com/airbnb/javascript#6.1
+  quoteProps: 'as-needed', // https://github.com/airbnb/javascript#3.6
+  jsxSingleQuote: false, // https://github.com/airbnb/javascript/tree/master/react#quotes
+  trailingComma: 'all', // https://github.com/airbnb/javascript#20.2
+  bracketSpacing: true, // https://github.com/airbnb/javascript#19.12
+  jsxBracketSameLine: false, // https://github.com/airbnb/javascript/tree/master/react#alignment
+  arrowParens: 'always', // https://github.com/airbnb/javascript#8.4
+  overrides: [
+    {
+      files: '.editorconfig',
+      options: { parser: 'yaml' },
+    },
+    {
+      files: 'LICENSE',
+      options: { parser: 'markdown' },
+    },
+  ],
+};