Provide intuitive documentation how to run the code

[marekgluza]

1. remove parser #92 provides an example but doesn't describe how to interpret it

The README example is very small so we should have a simple documentation script/notebook which additionally explains how to extract the energy gain and circuit depth

Originally posted by @marekgluza in #92 (comment)

2. Optimizer option (readability) #83
   when running VQEs it hasn't been clear what is happening; most of it will be closed by remove parser #92 but still might not be intuitive and explicit