Alan's Work on MrDocs and Handlebars

https://cppalliance.org/alan/2023/10/27/AlanQ3Update.html

MrDocs was refactored, CI automated, LLVM binaries updated, CMakePresets added, and a C++ Handlebars engine integrated with full tests. website Antora support, Boost.URL fuzz testing, release‑tool containers, and reusable C++ GitHub Actions were delivered.