also:
- added `formatter_flags::quote_infinities_and_nans`
- made constructors for dates/times accept any integral types
- lots of internal work on formatter base (laying groundwork for more customization)
There's no new functionality here. It's purely tooling + CI stuff:
- moved `python` => `tools`
- moved documentation images to subfolder
- moved `vs/tests` to tests/vs projects
- moved `vs` solution etc to root
- added semicolons to macros
- added cpp.hint to help VS intellisense
- migrated documentation generation to external lib