rework(docs): better, more readable docs

docs/PROJECT_STRUCTURE.md

@@ -0,0 +1,14 @@
+# Project Structure
+
+```
+ModLoader/
+├── WeaveLoader.Launcher/       # C# launcher executable
+├── WeaveLoaderRuntime/         # C++ DLL injected into the game
+├── WeaveLoader.Core/           # C# mod discovery and lifecycle
+├── WeaveLoader.API/            # C# public API for mod authors
+├── ExampleMod/                 # Sample mod
+├── build/                      # Shared build output
+├── WeaveLoader.sln
+├── README.md
+└── CONTRIBUTING.md
+```