Some other wikis offer a feature where a particular string in your text is substituted for a signature, e.g., ~~~~ is expanded to something of your choosing.

If you are using git, you can achieve something similar, at least for edits in a local clone of your repository, by leveraging Git filters.

To set this up for a local clone:

1. add this line to .git/info/attributes

    *.mdwn filter=signature
   

   You could choose to add this to .gitattributes instead, and commit that to the repository as well. You could also adjust the path match to your settings/tastes. Here, we are only applying this for edits to mdwn files.

2. Configure a "clean" filter for your local clone which performs the substitution, e.g.

    git config filter.signature.clean 'sed "s#~~~~#*— [[Jon]], $(date +%Y-%m-%d)*#"'
   

   "signature" here can be anything so long as it matches the name in the attributes file, above.