Release v0.21.0

What's Changed

Features

• Better search for exception origin by @lyrixx in #570
• Better rendering of run errors by @lyrixx in #571
• Add check() function to ensure requirements are met by @lyrixx in #573
• Add official support strings and var-dumper functions by @pyrech in #575

Internal

• Rework the releasing by @lyrixx in #569
• Rework our examples by @lyrixx in #572
• Fix exception handle by @lyrixx in #574

Full Changelog: v0.20.0...v0.21.0