Merge pull request #263849 from ElvishJerricco/sd-initrd-not-experimental

        stage 2 counterparts such as {option}`systemd.services`,

        except that `restartTriggers` and `reloadTriggers` are not

        supported.

        Note: This is experimental. Some of the `boot.initrd` options

        are not supported when this is enabled, and the options under

        `boot.initrd.systemd` are subject to change.

      '';

    };