`usb_devices` from `zpe.nodegrid.facts` module contains bogus data

[m-hau]

The zpe.nodegrid.facts module returns nonsense data for usb devices.

TASK [Gather facts] *********************
ok: [nodegrid] => 
    ansible_facts:
        [...]
        usb_devices:
        -   description: tion
            detected_type: ected type  kernel
            kernel_device: device  descrip
            usb_id: usb id  det
            usb_path: usb path
            usb_port: usb port
        -   description: ====
            detected_type: ==========  =======
            kernel_device: ======  =======
            usb_id: ======  ===
            usb_path: ========
            usb_port: ========
    changed: false

The cause seems to be that the ttp template uses the _start_ indicator to skip the headers, and the _headers indicator for automatic column detection. The former seems to be ignored when using the later, causing the header to be parsed instead of being skipped.