Issue: sed -i "s|ultrasecretkey|$(openssl rand -hex 32)|g" searxng/settings.yml works for UNIX-based system. For windows the sed command is not available.

Solution: Added a note on the README.md to indicate a corrected command alternative for Windows users to generate the secret key and write it into searxng/settings.yml file:

$randomBytes = New-Object byte[] 32
(New-Object Security.Cryptography.RNGCryptoServiceProvider).GetBytes($randomBytes)
$secretKey = -join ($randomBytes | ForEach-Object { "{0:x2}" -f $_ })
(Get-Content searxng/settings.yml) -replace 'ultrasecretkey', $secretKey | Set-Content searxng/settings.yml