Coding style new appendix

[fschledorn]

@nick75g Thanks for the updates to the coding style appendix! I have a few comments:

• Please don’t push to main or the release branch (new_features_2025) directly. Could you use a PR for this? It's important for code review and helps keep our commit history clean and understandable. Plus, using PRs makes our compile workflow action run more smoothly!
• please make sure to rebase before making any more changes or merging the PR (see Fix compile workflow #155).
• can you move the .cpp files into the files directory where all .cpp files are centrally managed and adjust coding_style.tex accordingly

[fschledorn]

@Xeldlie @Plebysnacc @calvalre
I have a few advanced suggestions what we could add:

• Add a section on file structure: Discuss how to organize code within files, including #include statements, function prototypes, and using namespace std;.
• DRY: Don’t repeat yourself and how to properly use encapsulation in that context
• Introduce the concept of header files and header guards: Explain their purpose and how to use them correctly.
• Discuss const correctness: Explain the importance of const for writing safe and reliable code.
• Introduce linters and formatters: Explain how tools like clang-format can help enforce coding style and improve consistency.
• Add "good vs. bad" code examples: Provide concrete examples to illustrate the benefits of good coding style.
• Create refactoring exercises: Give students hands-on practice in improving code style.

[nick75g]

My bad! Internet was extremely unstable during the weekend and I didn't notice I was pushing to #148 instead of #151.

[fschledorn]

My bad! Internet was extremely unstable during the weekend and I didn't notice I was pushing to #148 instead of #151.

yeah no worries, just thought I’d tell you