Changes

pySim-prog: rework documentation

The documentation for the classic pySim-prog application is a bit
sparse. Let's rework it so that it includes the most important
information that is required to operate pySim-prog. Let's also add
a section about how the batch mode and CSV files are used.

Related: SYS#4120
Change-Id: I1d1a65154cea7fa77428b412fcf8c7b4cba629b1