Confusing instructions in readme #585

Readme file states that I should clone this repository in case I won't be using Python:

It made me thinking that while using Python, rootfs.py will download repository contents automatically.
But no, it just throws error.

So lines about repository cloning should be moved above Python mention.

Before that, readme said about --mirror parameter and about instructions given by using --help parameter.

Problems are that:

1. --help does not mention --mirror parameter. There are only -m and --mirrors.
2. There are no instructions produced by using --help parameter. There is a list of parameters, all of which are optional.

I suggest to either add --mirror to --help or change it in readme to either -m or --mirrors.
Also it would be nice to actually have instructions, which are guaranteed to produce working .img file.
It is nice to tweak various parameters, but first of all at least some working result should be obtained.

Regarding running .img itself, I tried VirtualBox, which either crashes or hangs at /kaem.x86.
Trying it with Bochs as well revealed that it writes to addresses which it shouldn't (MMIO ranges).
No wonder it fails to work.

I like the idea of this project overall, but it looks like its quality needs substantional improvement, both from user-friendliness and technical side before I can call it success.