Convert example scripts from documentation to code-blocks except for those that generate outputs.

[profminton]

The example scripts are hard to copy-paste as is, as they render the full IPython output rather than just the code blocks. We need an alternative way to demonstrate use cases that is cleaner than the IPython sphinx directives. I propose a mix of .. code-block:: python directives to showcase examples followed by .. ipython:: python directives when required to show output. This might lead to unnecessarily complex documentation files, though, so another approach might be better.