* UI revamp WIP

* `Object-oriented`: Add simpler examples, update quiz and exercises (#249)

* add 2 new examples

* finish new examples

* finish new examples pt2

* update new examples with docstrings and improved tests

* add docstrings

* finish docstrings

* make sure that class methods are only using the class attributes to produce their results

* test that the return value is an instance of a custom class

* use closure to check for usage of class attributes

* update property section and quiz

* Expand docstring description of Exercise 4

* finish updating the exercises

* Minor changes

* Stupid metadata fix of the ipython notebook

* Fixing

* Replacing variable l: E741 Ambiguous variable name: `l`

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

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Co-authored-by: edoardob90 <edoardob90@gmail.com>
Co-authored-by: Snowwpanda <pascal.su@empa.ch>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

* Revamp UI of AI widgets

* Resolve flake8 errors

* Fix more UI inconsistencies

* Fix test in Object-Oriented Example 4 (#262)

* Add __eq__ validation in Example 4
* Add a comment to explain the rationale behind __closure__ testing

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Co-authored-by: edoardob90 <edoardob90@gmail.com>

* Fix errors found in the `input_output` notebook (#258)

* Fixing some issues with the input_output notebook
and changing some exercies a bit.

* Added an exercise to input_output notebook

* Added Docstrings to exercises

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* Changes for pre-commit

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* Variable naming consistent in tests.

* Reformulation program execution

Co-authored-by: Despina Adamopoulou <16343312+despadam@users.noreply.github.com>

* Review from despina fixes

* Resetting inputfiles after exercises (after writing to file is explained)

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* to_bytes function needs byteorder

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Despina Adamopoulou <16343312+despadam@users.noreply.github.com>

* Move quizzes to dedicated folder (#263)

* move quizes to folder
* Rename: quizes -> quiz
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Co-authored-by: edoardob90 <edoardob90@gmail.com>

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Co-authored-by: Despina Adamopoulou <16343312+despadam@users.noreply.github.com>
Co-authored-by: Snowwpanda <pascal.su@empa.ch>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>