Datasette-publish-vercel

- Fixed bug where using boolean settings such as `--setting allow_downloads 0` would cause deployments to serve 500 errors. [61](https://github.com/simonw/datasette-publish-vercel/issues/61)

- Fix for 500 error when run with latest `vercel/python` [58](https://github.com/simonw/datasette-publish-vercel/issues/58)

- Fixed bug caused by removal of `--no-clipboard` option in [Vercel 27.0.0](https://github.com/vercel/vercel/releases/tag/vercel%4027.0.0). [#57](https://github.com/simonw/datasette-publish-vercel/issues/57)
- Errors that occur when running the `vercel` command are now reflected in the exit status of `datasette publish vercel`.

- New `--crossdb` option for publishing a Datasette instance that has [cross-database queries](https://docs.datasette.io/en/stable/sql_queries.html) enabled. [#55](https://github.com/simonw/datasette-publish-vercel/issues/55)

- Fixed bug where the `invoke_startup()` method was not being called on startup, which caused Datasette plugins using [the startup() plugin hook](https://docs.datasette.io/en/stable/plugin_hooks.html#startup-datasette) to break. [54](https://github.com/simonw/datasette-publish-vercel/issues/54)

- New `--generate-vercel-json` option to generate the `vercel.json` that would be used and output it without running the deploy. [51](https://github.com/simonw/datasette-publish-vercel/issues/51)
- You can then edit that `vercel.json` file to add custom options, then pass it to the new `--vercel-json` option for a custom deployment. [51](https://github.com/simonw/datasette-publish-vercel/issues/51)
- `--template-dir` and `--plugins-dir` options now work, thanks Romain Clement. [41](https://github.com/simonw/datasette-publish-vercel/issues/41)
- `DATASETTE_SECRET` environment variable can now be used to set a persistent Datasette secret. Thanks, Romain Clement. [43](https://github.com/simonw/datasette-publish-vercel/issues/43)