Remove weird scroll bar on documentation website

### Are you submitting a **bug report** or a **feature request**?

I wanted to contribute on the documentation global CSS, but I did not found where it is 🤔

The purpose was to remove the weird horizontal scroll bars:


I founded that you use `styled-component` for the documentation website, but I did not found the components anywhere.
If you can guide me, I will open a PR on that.

If not, the following changes should be applied to remove those scrollbars

left bar (`div` with classes `sc-eqIVtm kRufpp sc-fBuWsC frLjbI`)
```diff
+ overflow-x: hidden;
```

right bar (`ul` with classes `sc-hzDkRC kpsoyz sc-Rmtcm dzELat`)
```diff
- flex: 0 0 240px;
+ flex: 0 1 240px;
```

Thanks