v2.4.0

What's Changed

• Add vsync::atomic C++ interface by @lilith218
• Generate API documentation by @lilith218
• Drop unused files and clean up cmake by @lilith218
• ARM-V8 and RISC-V verification by @radumcostache
• Documentation improvements including manpages by @db7

Full Changelog: v2.3.1...v2.4.0