Sync SDL3 wiki -> header

[ci skip]

include/SDL3/SDL_gpu.h

@@ -128,11 +128,14 @@
  * [blog post](https://moonside.games/posts/layers-all-the-way-down/)
  * explaining this situation.
  *
- * It is optimal for apps to pre-compile the shader formats they might use,
- * but for ease of use SDL provides a separate project,
+ * Shader binaries can be compiled using standard Vulkan, Direct3D or Metal
+ * tooling, but SDL provides a separate project,
  * [SDL_shadercross](https://github.com/libsdl-org/SDL_shadercross)
- * , for performing runtime shader cross-compilation. It also has a CLI
- * interface for offline precompilation as well.
+ * , as a convenient command-line wrapper for cross-compiling shaders from
+ * HLSL or SPIR-V to any backend format (SPIR-V, DXBC, DXIL, MSL).
+ *
+ * While offline ahead-of-time compilation is preferred, SDL_shadercross is
+ * also able to operate as a runtime library for advanced usecases.
  *
  * This is an extremely quick overview that leaves out several important
  * details. Already, though, one can see that GPU programming can be quite