Improve eslint rules (#3147)

* Add semi to ESLint rules

* Add padded-blocks to ESLint rules

* Add comma-dangle to ESLint rules

* add config/webpack and storyboard

* add streaming/

* yarn test:lint -- --fix

app/javascript/mastodon/features/compose/components/character_counter.js

@@ -6,7 +6,7 @@ class CharacterCounter extends React.PureComponent {
 
   static propTypes = {
     text: PropTypes.string.isRequired,
-    max: PropTypes.number.isRequired
+    max: PropTypes.number.isRequired,
   };
 
   checkRemainingText (diff) {