docs: make guide cross-platform and improve error handling resilience

docs/README.md

@@ -22,7 +22,26 @@ graphics programming experience. Every sentence teaches GPU concepts — not Rus
 - **01 — Rainbow Triangle** — The minimal complete program: one triangle, smooth color interpolation
 - More guides coming soon (textures, lighting, compute)
 
+## Running the Project
+
+From the project root:
+
+```bash
+cargo run
+```
+
+This works on all supported platforms. If you encounter build errors, see the
+**Prerequisites** section above for platform-specific build tool requirements.
+
 ## Prerequisites
 
 - Rust stable (edition 2024)
-- Linux x86_64 with Vulkan drivers (`libvulkan1`)
+- A system with a GPU supporting WebGPU-compatible APIs:
+  - **Windows:** Windows 10 or later with a DirectX 12-capable GPU
+  - **macOS:** macOS 10.13+ with a Metal-capable GPU
+  - **Linux:** Vulkan-capable GPU and drivers
+
+> **Build tools:** Your platform may require additional build tools:
+> - **Windows:** Visual Studio Build Tools (2019 or later)
+> - **macOS:** Xcode Command Line Tools (`xcode-select --install`)
+> - **Linux:** Vulkan ICD and development packages (e.g., `vulkan-validationlayers` on Ubuntu)