Currently lazygit looks for its config file in `XDG_CONFIG_HOME` if it's
available, but if not it falls back to the defaults defined by the
[xdg](https://github.com/adrg/xdg) package. Unfortunately the defaults
the package falls back to isn't what CLI applications commonly fall back
to on macOS. Specifically, it looks in `~/Library/Application Support`
instead of `~/.config`.
This updates the app config logic to:
- Look for `~/.config/lazygit` first if `XDG_CONFIG_HOME` is not set
and we're on macOS.
- Fallback to the existing `xdg` package location if the configuration
file exists there.
- Default to `~/.config/lazygit/config.yml` if `XDG_CONFIG_HOME` is not
set, we're on macOS, and there is no existing configuration file.
This change did feel a bit like having to thread a needle and I didn't
see any existing tests for this behavior (which is reasonable, since it's
complicated and OS dependent) so I did test a few variations of the
configuration locally by building with this change included and running
a `brew` installed lazygit.
It seemed to work properly, falling back to the existing location when
`XDG_CONFIG_HOME` isn't set, using `~/.config/lazygit` when `config.yml`
is present, and creating `~/.config/lazygit/config.yml` when it's not.
I think this should resolve https://github.com/jesseduffield/lazygit/issues/1341
