[Feature request] Documented clangd setup for CUDA kernel indexing

DeepGEMM already has a CMake path intended for IDE indexing, but clangd setup is currently not straightforward for CUDA headers.

In my local setup I needed:
- a dedicated `build-clangd` directory with `CMAKE_EXPORT_COMPILE_COMMANDS=ON`
- `pybind11`/Torch CMake prefixes passed explicitly
- `.clangd` CUDA flags for `.cuh` files, e.g. `-x cuda`, `--cuda-gpu-arch=sm_100`, `--cuda-path=...`
- removal of some nvcc-only flags
- a few diagnostic suppressions for CUDA 13.x / SM100 false positives

Would the project be open to adding either:
1. a short clangd setup section in the README, or
2. a helper script such as `scripts/configure_clangd.sh`, or
3. a checked-in template `.clangd.example`?

The goal would be reliable navigation/indexing for kernel development, not necessarily zero clang diagnostics for all CUDA intrinsics.