Emphasize development and debug utility of ipy command

The utility of the optional ipy command combined with self.self_in_py = True for developers is truly phenomenal. We don’t do these amazing features justice in our documentation and I’m not sure how discoverable they are for new cmd2 developers. These features open the door to an enhanced development experience that allows easy experimenting as well as the ability to do some after-the-fact debugging when things don’t behave like you think they should.

We should add a section on “Developer Tips” or something like that to our documentation.

[tleonhardt]

I like the concept of putting this in the basic oookiecutter template: https://github.com/jayrod/cookiecutter-python-cmd2/issues/10

We can probably also update our documentation a little to emphasize just how darn useful ipy is for debugging.

[kmvanbrunt]

In both py and ipy shells, you can do everything that’s possible in a pyscript. Therefore, you don’t need to call self.do_foo(). Just use app('foo arg1 arg2').

These shells offer a lot for debugging. I commonly do the following operations:

1. Check application state via self object.
2. Alter application state via self object to simulate various conditions.
3. Run commands via app command to see what’s returned in the CommandResult object.

I also use run_pyscript for debugging. Recently I wrote a pyscript which rewrites a do_* command function while the application is running. That way I don’t have to keep closing and reopening the application to test my code changes.