A thin wrapper over Google's Highway SIMD library to simplify its interface.This commit provides the implementation of that wrapper, consisting of:- simd.hpp: Main header defining the SIMD namespaces and configuration- simd.inc.hpp: Template header included multiple times with different namespacesThe wrapper eliminates Highway's class tags by:- Using lane types directly which can be deduced from arguments- Leveraging namespaces (np::simd and np::simd128) for different register widthsA README is included to guide usage and document design decisions.SIMD: Update wrapper with improved docs and type support  - Fix hardware/platform terminology in documentation for clarity  - Add support for long double in template specializations  - Add kMaxLanes constant to expose maximum vector width information  - Follows clang formatting style for consistency with NumPy codebase.SIMD: Improve isolation and constexpr handling in wrapper  - Add anonymous namespace around implementation to ensure each    translation unit gets its own constants based on local flags  - Use HWY_LANES_CONSTEXPR for Lanes function to ensure proper    constexpr evaluation across platformsUpdate Highway submodule to latest masterSIMD: Fix compile error by using MaxLanes instead of Lanes for array size  Replace hn::Lanes(f64) with hn::MaxLanes(f64) when defining the index array  size to fix error C2131: "expression did not evaluate to a constant". This error  occurs because Lanes() isn't always constexpr compatible, especially with  scalable vector extensions. MaxLanes() provides a compile-time constant value  suitable for static array allocation and should be used with non-scalable SIMD  extensions when defining fixed-size arrays.SIMD: Rename NPY_SIMDX to NPY_HWYRename Highway wrapper macros for clarity:- NPY_SIMDX → NPY_HWY- NPY_SIMDX_F16 → NPY_HWY_F16- NPY_SIMDX_F64 → NPY_HWY_F64- NPY_SIMDX_FMA → NPY_HWY_FMATo avoids confusion with legacy SIMD macros.