Support Imager's config.txt
**Is your feature request related to a problem? Please describe:**
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It would be nice to configure the image from the flasher's UI. Wi-Fi, time zone, password, ssh-key, etc.

**Describe the solution you'd like:**
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Implement the configuration via UI https://www.raspberrypi.com/news/raspberry-pi-imager-update-to-v1-6/

**Describe alternatives you've considered:**
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None really
**Additional context:**
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This would be a nice way to skip the Wi-Fi captive setup

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