direnv VS funky

I also made the export diff configurable, motivated by this post: https://github.com/direnv/direnv/pull/1233

Nice.

For years I've been using [direnv](https://direnv.net/) for this, setting environment variables which git picks up. This looks like a more feature complete equivalent, although to be honest I only really need switching of committer email and the SSH key used.

Direnv, for the uninitiated, loads and unloads environment variables when directories are entered and exited. Under every project folder there is a `$PROJ_DIR/.envrc` which contains:

buffer-env: A pure-Elisp version of the direnv utility. Useful to make Emacs aware of Python virtualenvs (which, judging by the questions posted here, is unfortunately still a complication for a lot of people). Similar to (and inspired by) envrc, but doesn't require the direnv program.

You can look at direnv to see this in action as they wrote shell hooks that get loaded into the shell profile and are executed on every prompt. https://direnv.net/

Yes, most Nix users employ https://direnv.net or the equivalent for your IDE of choice. Emacs for instance has https://github.com/purcell/envrc which set per-buffer variables.

The more applications I write, the more I tend to avoid typical config files in favor of using direnv [0] to set environment variables.

[0] https://direnv.net/

could combine it with something like: https://github.com/bbugyi200/funky

However, my favorite of this genre is the strangely named funky, which "takes shell functions to the next level by making them easier to define, more flexible, and more interactive."