Adding a way to map boost symbols to their reference page

cppreference.com has some nice ways to map, lets say, std::vector to their doc pages. You have a symbol table and their old search engine. Both make it quite convenient to learn about a symbol youre seeing somewhere (not just as a human, but also for programs/web scrapers). Making it possible for bots to find a symbol and link against their documentation is a huge benefit for beginners that never really got into boost.