Update script install-vbox-guest.md

https://github.com/ba1x/env-setup/blob/f2ced94fc71770035d3a8c1d2d38ef9e10faf658/docs/install-vbox-guest.md?plain=1#L13

ganti dengan versi terbaru

https://github.com/ba1x/env-setup/blob/f2ced94fc71770035d3a8c1d2d38ef9e10faf658/docs/install-vbox-guest.md?plain=1#L14

ganti dengan

```bash
sudo ./VBoxLinuxAdditions.run
```