The nixpkgs-unstable channel's programs.sqlite was used to identify
packages producing exactly one binary, and these automatically added
to their package definitions wherever possible.
Steps taken:
1. Clone https://github.com/Textualize/frogmouth
2. Change xdg to xdg-base-dirs or xdg_base_dirs per https://github.com/srstevenson/xdg-base-dirs/tree/6.0.0#xdg-base-dirs
3. Update the poetry lockfile with `poetry lock`
a. This required removing the Python 3.8 and 3.9 support in pyproject.toml
4. Generate a diff with `git diff`
5. Added this path to `pkgs/tools/text/frogmouth/default.nix`
6. Ran the resulting binary and saw that it worked.
Previously, this resulted in a stack trace where `frogmouth` was unable
to find `xdg` and could not start.
