Add Doxygen and document applyTranslator.hpp and loadUniversities.hpp

[GeorgeApos]

Closes #37

What

• Added a Doxyfile (generated with doxygen -g, then configured in a separate commit so the diff shows only the changes)
• Ignored the generated docs/ output
• Documented Utils::loadUniversities and Utils::applyTranslator, plus file-level and Utils namespace docs

Doxyfile choices

• INPUT = include src README.md, RECURSIVE = YES, FILE_PATTERNS = *.hpp *.cpp
• USE_MDFILE_AS_MAINPAGE = README.md – README is the landing page
• HAVE_DOT = NO – avoids a Graphviz dependency; can be switched on if we want class/include graphs
• MACRO_EXPANSION = YES + PREDEFINED for Q_OBJECT/signals/slots so Qt macros don't confuse the parser
• WARN_IF_UNDOCUMENTED = YES – the warnings double as a to-do list
• GENERATE_LATEX = NO – HTML only

How to build

doxygen Doxyfile
xdg-open docs/html/index.html

Ideas / follow-ups

• Doxygen gives us 16 warnings for undocumented files, could be follow-up issues.
• A GitHub Actions workflow could build the docs and publish them to GitHub Pages

[TolisSth]

Great idea and great work please implement the issues and take up the deployment of the github pages