github readme how to add collapsible section code example

Example: markdown click to expand

## Markdown collapsible section
<details>
  <summary>Click to expand!</summary>
  
  ## Heading
  1. Item
  2. list
     * Item
     * Item
```js
	console.log('code');
```

- code
	```js
		console.log('also code');
	```
</details>