Yubikey support for age

[Stefan Claas]

Hi all,

for those who use already modern age or rage (the Rust version)
instead of GnuPG, there is now a plug-in available, which allows
you to store your age secret key on a Yubikey.

https://github.com/str4d/age-plugin-yubikey

I tested it with age first, but age currently does not support
it and will have it in the next version. It already works fine
with rage.

Regards
Stefan