Add Rust for Linux material

[fw-immunant]

This will probably require a fair bit of discussion and revision, but this is how things stand at present. Notably, this material does not have exercises and might benefit from them to keep students engaged and improve pacing.

I taught this material in essentially this form (minus a couple typo fixes) to a group of around a dozen students with Linux kernel experience but not much Rust background other than the Fundamentals course. I thought things went well but also took some time to loop in some slides from the Concurrency section as a working understanding of Rust concurrency features is necessary to understand some safety patterns employed in the kernel. Maybe we should figure out a way to share slides or add "detours"?

Comments from RfL zulip here.

[fw-immunant]

The code references using the Linux kernel library will have to be disabled for testing, since we probably don't want to take the Linux kernel as a dependency.

[djmitche]

I don't have any knowledge of RfL, so I can't comment on the content itself. However, this should be structured as sessions, segments, and slides. That means a subdirectory of rust-for-linux for each segment, with an intro slide that just contains the timing macro. Right now, the files are all in the same directory. Is this a single session, or morning/afternoon? Ideally each segment would have an exercise, but that has proven difficult with all of the deep-dives. Still, some kind of pause-for-reflection every 30m-1h would be good, even if that's just some basic review questions.

You'll want to add references to this course in index.md`` and running-the-course/course-structure.md` as well.

[mgeisler]

Thanks @fw-immunant for putting this up! It's super exciting! 😄

Can you split every slide longer than ~20 lines into sub-slides? I want to avoid vertical scrolling while presenting.

As for the content itself, I also don't have experience with this. @Darksonn, would you be able to review this?