many broken links in tutor files

[jurgenvinju]

Describe the bug

• A lot of references throughout the documentation that do produce a link do not work correctly. As an example on https://docs.rascal-mpl.org/unstable/Rascal/#Values-ReifiedTypes clicking on https://docs.rascal-mpl.org/unstable/Rascal/#Libraries-Prelude-Type opens the "Rascal Language Reference" page, not to a page about the Type library.

via @Pieter007

Those are bugs in the tutor compiler or left-overs from migrations from earlier markdown formats. We have to go through all of them!

[jurgenvinju]

Example:

2.2. Call Analysis:
     - [$Rascal:Expressions/Reducer]: This is probably intended to be a link