Adapt nav tree view of the website

docs/documentation/sizing.md

docs/download/getting-started.md

docs/get-involved/build-environment/linux.md

docs/get-involved/build-environment/macos.md

docs/get-involved/build-environment/mingw.md

docs/get-involved/build-environment/windows.md

docs/get-involved/build/cpp.md

docs/get-involved/build/general.md

docs/get-involved/build/python.md

docs/get-involved/cmake-presets.md

docs/get-involved/contribute.md

docs/get-involved/developer-installation.md

docs/get-involved/get-source-code.md

docs/get-involved/ide-setup.md

docs/get-involved/including-libraries.md

docs/get-involved/merge-request.md

docs/get-involved/release-package.md

docs/get-involved/review-merge-request.md

docs/get-involved/style/cpp-modularization.md

docs/get-involved/style/cpp.md