Dmitry's Q4 2023 Update

https://cppalliance.org/dmitry/2024/01/12/dmitrys-q4-update.html

In Q4 2023, direct JSON parsing was finalized and merged into Boost 1.84.0. Work then shifted to direct serialization using boost::json::serializer, with performance optimizations explored. CI and coverage tools identified dead code, and completion is targeted before the next Boost release.