repository will be assumed to be upstream.
+
Optional <path> arguments limit which submodules will be initialized.
-If no path is specified, all submodules are initialized.
+If no path is specified and submodule.active has been configured, submodules
+configured to be active will be initialized, otherwise all submodules are
+initialized.
+
When present, it will also copy the value of `submodule.$name.update`.
This command does not alter existing information in .git/config.