Cover "Bundled Applications" as an additional topic

We currently don't cover the question of "all inclusive" applications at all, where the whole of the application is bundled up into a single file. While that's beyond the scope of PyPA's responsibilities from a development perspective, we can still provide a useful index pointing folks towards the tools and communities that do address this problem space.

There are two main approaches to cover: those that assume a Python runtime will be available on the target system, and those that bundle the Python runtime as well.

Options that expect a runtime to be available:

• zipapp (standard library): https://docs.python.org/3/library/zipapp.html
• pex: https://pex.readthedocs.io/en/stable/

Options that bundle the runtime as well:

• PyInstaller (Windows, Mac OS X, Linux, *nix): http://www.pyinstaller.org/
• cx_Freeze (Windows, Mac OS X, *nix: https://cx-freeze.readthedocs.io/en/latest/
• py2exe (Windows): http://www.py2exe.org/
• py2app (Mac OS X): https://pythonhosted.org/py2app/
• briefcase (iOS, tvOS, macOS, Android): https://briefcase.readthedocs.io/en/latest/

Inizia individuando la pagina della guida al packaging o l'area di navigazione in cui sono documentati gli argomenti relativi alla distribuzione delle applicazioni. Aggiungi una panoramica delle applicazioni in bundle, separando gli strumenti che richiedono un runtime Python esistente da quelli che ne includono uno, e includi i progetti elencati con le piattaforme supportate. Il lavoro è completato quando i lettori possono usare la pagina come indice di questi strumenti e community.