feat #  prototype for section refresh animation

implementation of the section refresh animation
There is no need to clone the full node, as its content is later replaced with innerHTML.
You could simply do:
```js
this._newSection = this._domElt.cloneNode(false);
```
You can check the [cloneNode documentation](https://developer.mozilla.org/en-US/docs/Web/API/Node.cloneNode).