Closes #42 🐔️👍️
Approved-by: belazy <aarthuur01@gmail.com>
Approved-by: v-lafeychine <vincent.lafeychine@proton.me>
Approved-by: aalbert <augustin.albert@bleu-azure.fr>

🦀️🍰🦀️🍰🦀️🍰

* chore(language): typo hunting

* chore(kernel/type checker): adapt type checker tests to new kernel interface

* chore(kernel/test): adapt `and.rs` test to new kernel interface

* chore(proost): adapt proost to new kernel interface

* chore(parser): adapt parser to new kernel interface

* doc(kernel): complete documentation and interface

* doc(kernel/builder): WIP

* doc(kernel/calculus): complete documentation for calculus.rs

* doc(arena): complete documentation for arena.rs

* doc(kernel/arena): WIP