CI/CD, release, and publish process improvements

As we start to work with a few partner users it'll quickly become important to develop shared expectations around changelogs, releases, migrations, access to built images, etc... 

Let's start to track those tasks here. 

```[tasklist]
### Tasks
- [x] Github workflow to build image for every PR
- [ ] Define process for releases
- [x] Docker-compose workflow improvements
```
