New Features
- add `shell.run_async` ([63](https://github.com/AnswerDotAI/execnb/pull/63)), thanks to [comhar](https://github.com/comhar)
- Use pygments for md output rendering ([62](https://github.com/AnswerDotAI/execnb/issues/62))
- Add optional image rendering control to `render_outputs` ([61](https://github.com/AnswerDotAI/execnb/pull/61)), thanks to [ncoop57](https://github.com/ncoop57)
- Add option to use ansi2html renderer ([57](https://github.com/AnswerDotAI/execnb/pull/57)), thanks to [Isaac-Flath](https://github.com/Isaac-Flath)
Bugs Squashed
- Missing execution count in run cells ([65](https://github.com/AnswerDotAI/execnb/issues/65))
- Fix matplotlib rendering in `render_outputs` ([64](https://github.com/AnswerDotAI/execnb/pull/64)), thanks to [johnowhitaker](https://github.com/johnowhitaker)