Merge all the existing tutorials into 1 big tutorial

[Esantos93]

The tutorial should include step-by-step explanations that address the following issues:

• How to create a MAL-language file from scratch and how to simple load/use an already existing file.
• How to programatically create model.
• How to use the mal-gui,
• How to use the malsim-gui.

Also, exampleLang should be used in the tutorial (when possible). This big tutorial might be later divided into smaller pieces (this has to be further discussed)

[mrkickling]

I talked to @mathiasekstedt about this, and writing it here now. I think we should close this PR and not merge the tutorials.