Fix some issues in README

README.md

@@ -4,9 +4,6 @@
 
 > Curated collection of useful React snippets that you can understand in 30 seconds or less.
 
-> *This README is built using [markdown-builder](https://github.com/30-seconds/markdown-builder).*
-
-
 #### Related projects
 
 * [30 Seconds of Code](https://30secondsofcode.org)
@@ -706,7 +703,9 @@ Finally, in the `render()` method, use a `<div>` to wrap everything and render t
   .dialog-content {
     min-width: 300px;
   }
-```,```jsx
+```
+
+```jsx
 class ModalDialog extends React.Component {
   constructor() {
     super();
@@ -892,7 +891,9 @@ Define `changeTab`, which will be executed when clicking a `<button>` from the `
 .tab-menu > button:hover {
   border-bottom: 2px solid #007BEF;
 }
-```,```jsx
+```
+
+```jsx
 class Tab extends React.Component {
   constructor(props) {
     super(props);