Integrate keyring

[bjornsnoen]

Right now this app saves user credentials in clear text in the toml config. Needless to say this is not safe. I'm not familiar with the go package ecosystem so I don't know what to recommend but I'm certain something like keyring for python exists for handling secrets in go.

[mrusme]

It would be possible to integrate https://github.com/99designs/keyring in order to save the credentials to a keyring.

[RobertKosten]

If possible I'd like the option of using a cli password manager (e.g. pass), so a simple way to evaluate a shell command for a config key would be great. For example by using backticks, like newsboat does it: https://newsboat.org/releases/2.41/docs/newsboat.html#_shell_evaluation