Add basic example

[peppergrayxyz]

Currently, it is difficult to figure out how all parts play together. There is documentation available, but it needs to be pieced together. To make things easier, it would be great to have a basic kernel that is compiled into a basic OS and booted.

Addition in this PR:

• showcase an OS that boots a minimal kernel using bootloader
• update usage guides
• describe the setup of basic-os with basic-kernel in tutorial.md
• use bashtestmd to create a shell script from the tutorial
• run the shell script to generate the basic example
• boot the basic example using qemu and show that it starts and prints a message
• add generation of basic example from tutorial to CI

This gives newcomers a starting point and can serve as a template for new projects. By generating the basic example from the tutorial and adding this to CI the tutorial and basic example stay consistent and recent.

[Freax13]

Thank you for your contribution!

I welcome improvements for our documentation, but I'm not sure that this is going in the right direction. While it's impressive that you can create a full kernel from a bash script generated from a Markdown file, a lot of the sections just contain some commands without much of an explanation of what's going on. In part that's because the tutorial is generating each and every file and sometimes there just isn't much to say. Given this, I'm not sure how the Markdown file adds much value over just providing the files for the user to look at and adding inline comments to add more explanations.
Markdown aside, I like your example. It's cleaner than our tests and looks like a solid base for kernel. I'd welcome keeping that and linking it from our existing usage guide.
I'd prefer improving our existing usage guides instead of replacing it with a new one.

[peppergrayxyz]

Thanks for your Feedback!

I removed the tutorial and updated usage guides. Please take a look if this is going in the right direction now. Happy to make further adjustments!

[Freax13]

Great work so far! This is almost ready.

[Freax13]

Suggested change

	```toml
	# .cargo/config.toml
	[build]
	target = "x86_64-unknown-none"
	```

Let's also remove this.

[Freax13]

If we're specifying the command used to create the top-level crate (cargo init --bin we should do the same for the kernel). We could remove the kernel from the members (and just use members = []) and then use cargo new kernel --bin in the workspace root.

[Freax13]

Suggested change

	$ cargo run -- bios
	$ cargo run bios

Let's be consistent with the documentation in create-disk-image.md.

(Also applies to the command below for UEFI)