add prettier, update a few rules

src/index.js

@@ -0,0 +1,5 @@
+module.exports = {
+  base: require('../base'),
+  react: require('../react'),
+  prettierConfig: require('./prettier'),
+}

src/prettier.js

@@ -0,0 +1,12 @@
+// https://prettier.io/docs/en/options.html
+module.exports = {
+  printWidth: 120,
+  tabWidth: 2,
+  useTabs: false,
+  semi: true,
+  singleQuote: true,
+  trailingComma: 'all',
+  bracketSpacing: true,
+  jsxBracketSameLine: false,
+  arrowParens: 'always',
+};

src/react/rules/react.js

@@ -18,6 +18,6 @@ module.exports = {
     arrow: 'parens-new-line',
     condition: 'parens-new-line',
     logical: 'parens-new-line',
-    prop: 'parens-new-line'
+    prop: 'ignore',
   }],
 };