E5SubBot didn't support Docker deployment because MySQL is too bloated. Now it supports sqlite, I think that Docker deployment should return, which is also currently recommended.
Please check the README for specific deployment.
As for other updates, there is almost nothing, I refactor some code, update some badges, just this.
If there is no special needs, you don't need to update
Full Changelog: v0.3.2...v0.4.0