Dokku installation part missing

[HNTQ]

Bug report

Describe the bug

During your #394 you remove redundant dokku installation part but i can't find installation procedure on your website now.
So when i follow the getting start page, then the installation page i have an error message:

Coming back to getting start page but there is no dokku installation part .

You might forget to paste this paragraph in your installation page or delete it by inadvertence from getting start page:

### Install dokku on your Droplet

From your Docker Droplet run these commands :

```sh
wget https://raw.githubusercontent.com/dokku/dokku/v0.24.9/bootstrap.sh
sudo DOKKU_TAG=v0.24.9 bash bootstrap.sh