Suggested edits to the interrupts chapter

[Tomer-Eliahu]

I think this chapter is really good! It explains stuff very clearly.

I did find some typos and some things I think should be added.

[BartMassey]

I don't think we should explain further about proc macros here; it's a complicated concept in its own right. Maybe link to the Book of Macros?

[Tomer-Eliahu]

Fair enough, I think maybe link to the Macros section in the Rust Book (which then itself links to the Book of Macros)?

From skimming these just now, while the Book of Macros mentions ways to expand macros (like the Playground option), they don't mention the rust-analyzer command.

I think maybe it is worth mentioning briefly how to expand macros, so that someone reading this can get a quick understanding of roughly what the interrupts macro does without having to learn Macro syntax.

[BartMassey]

Thanks much for all your suggestions! We'll improve things as a result.