0.57a1

• Docker image now allows apt-get install. #1320
• ?_col= and ?_nocol= options to show and hide columns in a table, plus UI for doing this in the column cog menu. #615
• New ?_facet_size=max option, linked to from the … on truncated facets. #1337
• Heroku runtime used by datasette publish heroku is now python-3.8.10.
• Multi-arch support for built Docker images using Buildx - thanks, Blair Drummand. #1319