Improve the documentation for getting data "out of NWB" into publication figures

[jeromelecoq]

The documentation for reading from NWB files could be strengthened with real-like application of creating scientific figures from NWB files. Current documentation shows how to access individual items but shows minimal examples of scientific analysis performed from NWB files. Having those as part of the documentation and/or with linked notebooks will help further adoption by the community.

There are already a number of paper published that created second generation analysis from NWB files created at the Allen for example. This could serve as a sandbox to create those examples.