v2.0.0

This release marks a big step with regards to support for async:

• Refactor to go async by @almarklein in #41
• A bit more docs on async by @almarklein in #44

Further improvements:

• Handle ctrl-c by @almarklein in #25
• Add backend overview to docs by @almarklein in #43
• Fix rendering via bitmap adapter by @almarklein in #45
• Run examples on ci by @almarklein in #23

Changes to the API:

• Rename is_closed() to get_closed() by @almarklein in #26
• Remove run function by @almarklein in #42

Full Changelog: v1.0.0...v2.0.0