Document passing arguments to main()

[marcelstoer]

Addresses #406

[projectgus]

Hi @marcelstoer ,

Thanks for sending this. I've been reluctant to document any of these approaches as I'm ashamed they're still necessary, but maybe this will spur me on to make a better Python API. :)

Hopefully someday soon this section can be deleted. Most likely this approach will remain compatible for all future versions though, as it's straightforward to keep the implementation like this.

[marcelstoer]

Most likely this approach will remain compatible for all future versions though

It's a relief to hear that! For my use case that "API" is perfect. However, I do understand that any other application that integrates esptool to use only individual functions needs something else.