[clang] [clang] Add sections to C++ DR status page (PR #165749)

[Richard Smith via cfe-commits]

zygoloid wrote:

> I'm not sure that combining the columns will help enough to save horizontal space, but it will come at the expense of readability of stable names as pointed out [on the CWG reflector](http://lists.isocpp.org/core/2025/10/18649.php). Maybe we should drop section numbers instead?

Works for me. Or we could force a linebreak between the number and the name. Would that significantly increase the vertical space used by the table?

https://github.com/llvm/llvm-project/pull/165749