Issue in S/MIME blog post

We were notified that the article is missing a step.

I followed the instructions shown in https://software.hifis.net/tutorial/2020/04/15/smime-signing-git-commits , and it almost worked. I had to set the following git config too:

$ git config --global gpg.program gpgsm

It appears git version 2.25.1 defaults to gpg on Pop!_OS Linux 20.04.

Please also verify if there is a difference between the operating systems when working on this issue.

The article was introduced by #138 (closed).