Poxy

- fixed doxygen's `ref` links to `id` anchors on the same page being treated as external links
- added auto-linking for C++ [named requirements](https://en.cppreference.com/w/cpp/named_req)
- minor style fixes

- fixed crash regression with Doxygen 1.9.7
- fixed issues with \[tag\] substitution
- minor style fixes

- migrated to `pyproject.toml`
- fixed footer being off-center (24) (wroyca)
- fixed redundant `auto` in trailing return types (26) (wroyca)
- added config option `sponsor`
- added config option `twitter`

- allowed the use of square-bracket \[tags\] in more places

- fixed overlong `template<>` lines in summary views
- fixed function parameter names greedily wrapping in details tables

- fixed overlong `template<>` lines in page headers (they now wrap)