[Feature Request] Support docker secrets

[Axolord]

It would be nice if the image would also support docker secrets

Maybe I'll look into this in the coming months and open a pull request, if I am successful :)

[Axolord]

I did look into supporting docker secrets, but decided to build them into another netcup dyndns client.
For people that are interested, you can have a look at: https://github.com/Axolord/dyndns-netcup-go

But I still think it would be really nice, if this image would also support docker secrets and running as non-root user.

[LordWurstebrot]

I did look into supporting docker secrets, but decided to build them into another netcup dyndns client. For people that are interested, you can have a look at: https://github.com/Axolord/dyndns-netcup-go

But I still think it would be really nice, if this image would also support docker secrets and running as non-root user.

Thank you for your work, much appreciated!