Galette

The installer has 8 screens. All of them require a click. 4 of them requires extra info. 4 of them only a click (see #1845).

I suggest to that the admin who installes Galette, can provide an "answers-file" for the installer, so there is no need to type and click.

It could be `installer-options.inc.php` in the config folder.

See attached screenshot: Suggesting that all fields and buttons marked in blue can be auto filled and auto clicked (in addition to #1845)

Screen 1: Automatically choose new or update
Screen 2: Automatically enter info (already possible through config.inc.php, but the screen should be skippable)
Screen 3: Skip/autoclick - #1845
Screen 4: Skip/autoclick - #1845
Screen 5: Automatically enter info (from `installer-options.inc.php`) and click
Screen 6: Automatically select telemetry setting (and registration settings?) and click
Screen 7: Skip/autoclick - #1845
Screen 8: Skip/autoclick - #1845