feat: improve visibility of Install button on keyboards with long descriptions

Some keyboards (e.g. [gff_amharic](https://keyman.com/keyboards/gff_amharic?bcp47=am)) have a very long description so that the green "Install keyboard" button is not visible without scrolling. This makes it hard to use, especially on the desktop platforms where we display that page in a dialog and where the user is used to have the buttons with the available actions visible without having to scroll.

Maybe we should display the "Install keyboard" button at the top of the page? Or collapse the description to the first few lines so that the button is initially visible without having to scroll?

After scrolling down quite a bit we can now see the Install button - if we know that we have to scroll to get to it...