Doxygen is a documentation tool which can automatically generate code documentation from source code and external files (like Markdown). Right now, Doxygen is included in the `Makefile` of the project but does not quite do its job. It reads all Markdown files (`*.md`) of the project, but all Fortran source files are ignored. This needs to be fixed. To generate documentation, enter the project directory and call ```bash make docspdf ``` This will generate the `build/doc/html/index.html` (can be viewed in a browser) and `build/Documentation.pdf` files, which contain all information found by doxygen. To have doxygen recognize source code, the Doxyfile (located at `doc/Doxyfile`) needs to be modified. It contains much descriptions on what each option does, which should (hopefully) be enough to work with. The following things should be included in the documentation: - All source code located inside the `src` and `app` directories of the project. - All Markdown documents, like `README.md` and all documents of the `doc` directory. The `test` and `build` directories however should *not* be included in the documentation. If it is somehow possible, it would be nice to order the sections of `Documentation.pdf` in a kind that Reko-Direkt documentation comes before that of the FMU. This step is optional.