Feature request: macros in settings

I'd like to be able to store local or global snippets of text and invoke them with a shorthand. E.g. I want Claude to commit changes, but I want it to remember custom instructions. I'd like to be able to store a commit macro in the settings folder (e.g. as a text file) and then invoke it with $commit or something along those line.

I can approximate this now by saving a file called macro/commit and invoking it with @macro/commit but then I have to copy those files everywhere I use Claude.