I want to be able to re-use it between different source control systems
(e.g: `jj`).
As a first step, extract it to a proper module so that I can have it
live in a single space.
I remember why I didn't set it globally now, it's because `git blame`
complains and errors out, rather than silently ignoring the setting,
when the file doesn't exist in a repo...
This reverts commit 5ae2eacd49.
This should ensure that they will be included at the very end of the
configuration, even if other modules add more includes.
Notably, this ensures that the local configuration can override any
other setting.
