* guix/scripts/git/authenticate.scm (%default-options): Remove
‘keyring-reference’.
(config-value, configured-introduction, configured-keyring-reference)
(configured?, record-configuration, current-branch): New procedures.
(guix-git-authenticate)[missing-arguments]: New procedure.
Use ‘configured-introduction’ when zero arguments are given.
Use ‘configured-keyring-reference’ when ‘-k’ is not passed. Add call to
‘record-configuration’.
* doc/guix.texi (Invoking guix git authenticate): Document it.
Change-Id: I66e111a83f50407b52da71662629947f83a78bbc