Dmitry's Q2 2024 Update

https://cppalliance.org/dmitry/2024/07/12/dmitrys-q2-update.html

Direct parsing, extended serialisation and try_ accessors with source_location are now supported by Boost.JSON; a temporary proxy conversion is pending. Docs are generated by Docca using Jinja, and staging‑prefix installs are supported by Boost.Build.