Convert private_dot_config/git/config to config.tmpl so that the
[user] name/email can be overridden per host/user via the existing
`configs` key in .chezmoidata/hosts*.yaml, falling back to the
default identity (Xavier Logerais / xavier@logerais.com) when no
override is defined.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
