Add pvoSID example to sbfspot README

[jeena]

Because I've been struggling with not being able to upload anything to pvoutput.org - while I even copy and pasted the System ID from the website to the configuration to not mix up any numbers - I looked into the source code and found better instructions in the file sbfspot/rootfs/usr/bin/sbfspot/SBFspotUpload.default.cfg. This is why I copy and pasted them into the README, so that other people don't need to struggle to understand what the numbers before the : in the example mean.

[habuild]

Hi,

I updated the readme with a clearer example of the SBFspot options. This file is trying to commit to the test version of the addon, so will be closed.