wrong position of babel config example (#1057)

Author: I am not shine

README.md

@@ -512,11 +512,6 @@ export default class Error extends React.Component {
 
 ### Custom configuration
 
-<p><details>
-  <summary><b>Examples</b></summary>
-  <ul><li><a href="./examples/with-custom-babel-config">Custom babel configuration</a></li></ul>
-</details></p>
-
 For custom advanced behavior of Next.js, you can create a `next.config.js` in the root of your project directory (next to `pages/` and `package.json`).
 
 Note: `next.config.js` is a regular Node.js module, not a JSON file. It gets used by the Next server and build phases, and not included in the browser build.
@@ -551,6 +546,11 @@ module.exports = {
 
 ### Customizing babel config
 
+<p><details>
+  <summary><b>Examples</b></summary>
+  <ul><li><a href="./examples/with-custom-babel-config">Custom babel configuration</a></li></ul>
+</details></p>
+
 In order to extend our usage of `babel`, you can simply define a `.babelrc` file at the root of your app. This file is optional.
 
 If found, we're going to consider it the *source of truth*, therefore it needs to define what next needs as well, which is the `next/babel` preset.