added readme

README.md

@@ -0,0 +1,34 @@
+Spacetris SDL3
+=============
+
+A native C++20 SDL3-based Tetris-style game.
+
+Quick Start (Windows)
+- Install vcpkg and packages: `vcpkg install sdl3 sdl3-ttf --triplet=x64-windows`
+- Configure: `cmake -S . -B build-msvc -DCMAKE_BUILD_TYPE=Debug`
+- Build: `cmake --build build-msvc --config Debug`
+- Run (helper): `.
+build-debug-and-run.ps1` or run `build-msvc\Debug\spacetris.exe`
+
+Production Packaging
+- Quick package (uses existing build): `.
+package-quick.ps1`
+- Full production (clean Release build + package): `.
+build-production.ps1 -Clean`
+
+Tests
+- Unit tests target: `spacetris_tests` → exe `spacetris_tests.exe`
+- Run tests: configure+build then `ctest -C Debug` or run the test exe directly
+
+Where to look
+- Main app sources: `src/` (entry `src/main.cpp`, app `src/app`)
+- Build control: `CMakeLists.txt` and `cmake/ProductionBuild.cmake`
+- Packaging helpers: `build-production.ps1`, `package-quick.ps1`
+
+Notes
+- The canonical executable name is `spacetris` (`spacetris.exe` on Windows).
+- Assets live in `assets/` and are copied into the distribution package.
+
+If you want, I can:
+- Run a Debug build and confirm the test executable name,
+- Replace remaining legacy "tetris" tokens across generated files and docs.