Update to version 0.3.2

[lossyrob]

This PR updates the version to 0.3.2

• Ran scripts/stageversion 0.3.2
• Renamed the migration file from .sql.staged to .sql
• Updated CHANGELOG - I only added an entry for this release; there were previous releases without entries that I left a TODO for (cc @bitner)

Once this is in main, I'll tag main into a new release.

Note that this doesn't follow exactly the release process described in the README, but based on #41 I'm not sure we were exactly following that process. The process as described would not update the version in main but instead increment things in the tag. Instead I'm making the changes in this PR, merging into main, and tagging from main. I think this results in the same effect, is similar to the process that was used for 0.3.1, and will keep main up-to-date with versions. If this is the way we want to go we'll need to update the README