having some Qt-SDK without help files. Using help inside a browser is possible, but cumbersome. and local help would be nice for quick parameter-checks.
Found also the official docu at: http://download.qt-project.org/online/qtsdkrepository/windows_x86/desktop/qt5_5121_src_doc_examples/qt.qt5.5121.doc/ as 7z-archive.
Then add it via QtCreator > Tools > Options > Help > Documentation > “add the QCH files”.