Add option to output "trusted" certificates

[michelcve]

Would it be possible to add an option to output the full certificate chain as "trusted" (BEGIN TRUSTED CERTIFICATE, as like openssl -trustout)?

I need this for an application that only accepts trusted certificates. Of course I could split the fullchain, get it through openssl, and merge it back together, but it would be far more convenient if your tool would support it :-)

[zakjan]

Hi, sounds good, feel free to send a PR :)