New content and more exercises

Less than 10 days before the exam, so we (I and @EmanueleC) are trying to bring these stuff together.

We have added new content and some exercises (with solutions). I hope you enjoy it! 🎉 Btw, this is not a "stable" release, so be aware of grammatical horrors and similar stuff. In particular some content is missing (see #18).
The assembly exercise is also missing!

Have a good read 📖 📚