Add explanations to examples in documentation

[almson]

Without explanations of the many different ways to specify parameters, figuring out how to use this library is harder than it should be.

Also, most of the examples seem to demonstrate passing just a single parameter (or a set of parameters for a single invocation). It's not obvious how to pass several parameters.

[zbychupragmatists]

We know that our documentation is outdated and lacks many features we introduced. We will tried to update it but any help is appreciated.