CipSoft-Tibia/Qt5 — reverse-engineered prompt

I want you to set this repo up so I can build the custom Qt 6 source used by the Tibia client without having to understand the whole Qt build process.

Please inspect the project, make sure the normal build works, and add simple helper scripts or clear commands for Windows, Linux, and Mac where it makes sense. It should check or clearly explain the needed tools, like a C++17 compiler, CMake, Ninja, and Python 3. The default build should configure Qt with the install prefix inside qtbase, then run the build. Also make it easy to choose release, debug, or developer style builds.

Please do not rewrite Qt itself unless something is actually broken. Focus on making the repo easy to clone, configure, compile, and optionally build docs. Add a short practical README section for someone like me who just wants to get a working local build. Look up the current Qt build docs online if you need to.