No modules, no functions generation

[JacquesCarette]

We would like to generate code (like Projectile) with no functions at all (see #3247), just straight-line code. So we need a 'single function' option to the generator as a starting point.

As part of this task, the commit https://github.com/JacquesCarette/Drasil/commit/f2f547cc749e82e639b55167c713fb2509473c9c should be cherry-picked (and finished, i.e. changes to stable dealt with) along with modified to use that new option.

[cd155]

As far as I know, this chart might be helpful in visualizing the current hierarchical structure of Choices

I guess the modularity part may need to be re-work, and adding a single function option under unmodular?

[JacquesCarette]

Thanks Dong - yes, that should help a new person navigate the current choices!