Datasette-explain

- Now tested against both Datasette 0.64.x and the Datasette 1.0 alphas
- README includes a screenshot and a link to [a demo](https://datasette.simonwillison.net/simonwillisonblog?sql=select%0D%0A++blog_tag.tag%2C%0D%0A++blog_blogmark.link_title%2C%0D%0A++blog_blogmark.link_url%0D%0Afrom%0D%0A++blog_blogmark_tags%0D%0A++join+blog_tag+on+tag_id+%3D+blog_tag.id%0D%0A++join+blog_blogmark+on+blog_blogmark_tags.blogmark_id+%3D+blog_blogmark.id%0D%0Aorder+by+blog_blogmark.id+desc)
- Switched from `setup.py` to `pyproject.toml`

- Fixed a bug where `explain` queries showed an error because you can't explain an explain. [5](https://github.com/simonw/datasette-explain/issues/5)

- Fix for "You did not supply a value for binding parameter" error. [4](https://github.com/simonw/datasette-explain/issues/4)

- `:param` parameters in SQL queries are now supported. [3](https://github.com/simonw/datasette-explain/issues/3)

- Initial alpha release. [1](https://github.com/simonw/datasette-explain/issues/1)