Improve markdown writing experience (use anchors and line formatting)

[iolivia]

Using anchors will make it less painless to make changes without breaking the markdown and we could also use the line hiding feature of mdbook to make some of the explanations better by highlighting which lines are new/modified. High effort though, a good starting point might be doing this for new code.

https://rust-lang.github.io/mdBook/format/mdbook.html

• Chapter 1
• Cahpter 2
• Chapter 3

[iolivia]

Closing this as it's not a priority atm and likely high effort.

[iolivia]

Reopening as it is very very annoying to make any change without breaking the whole book. Need a strategy for this, maybe a good first step is using it on new code and slowly adding it to old code.