sigmatch issues

Problems compiling on the latest version of msvc

``` C:\PROGRA~1\MICROS~3\2022\ENTERP~1\VC\Tools\MSVC\1437~1.328\bin\HostX64\x64\cl.exe /TP -IE:\vcpkg\buildtrees\sigmatch\src\v0.2.0-bf43ea0aed\include /nologo /DWIN32 /D_WINDOWS /W3 /utf-8 /GR /EHsc /MP /MD /O2 /Oi /Gy /DNDEBUG /Z7 -std:c++20 /showIncludes /Foexamples\CMakeFiles\02.custom_reader.dir\02.custom_reader.cpp.obj /Fdexamples\CMakeFiles\02.custom_reader.dir\ /FS -c E:\vcpkg\buildtrees\sigmatch\src\v0.2.0-bf43ea0aed\examples\02.custom_reader.cpp E:\vcpkg\buildtrees\sigmatch\src\v0.2.0-bf43ea0aed\include\sigmatch/sigmatch.hpp(624): error C2512: 'std::array': no...

jimwang118

C++ 20 Module Version

This is already a C++ 20 library so why not have a version of this library that comes as a single C++20 module interface definition file instead of a header,...

KeinNiemand