Questions regarding Docker integration

Hey!

I'm an Umbrel active contributor and I'm currently looking into a Docker implementation, following Umbrel requirements (e.g. prebuilt images). I've a few questions regarding this.

[Here is](https://github.com/louneskmt/umbrel/blob/dd2768b87423a6f6f00c5c9d47d0539569847fcc/apps/ion/docker-compose.yml) an example of what it could look like. Please note that this is an early not-working version.

1. **Configuration logic**

Your [install guide](https://github.com/decentralized-identity/ion/blob/master/install-guide.md) specifies that the build command (`npm run build`) has to be executed every time a configuration JSON file is modified. This command corresponds to the following:

https://github.com/decentralized-identity/ion/blob/11481c35ca9af3a4bb9390b92501567d22fd3270/package.json#L54

which compile Typescript files and copy configuration files from `json` and `tests` to the `dist` dir.

Does this need to be run even if the config files paths are not set to default (i.e. `ION_BITCOIN_CONFIG_FILE_PATH`, `ION_BITCOIN_VERSIONING_CONFIG_FILE_PATH`, `ION_CORE_CONFIG_FILE_PATH`, `ION_CORE_VERSIONING_CONFIG_FILE_PATH` are set to custom values)? If not, would it be possible to run the `tsc` only once on build? This allows to build `ion` in the [Dockerfile](https://github.com/louneskmt/ion/blob/docker-images/docker/ion-core/Dockerfile) instead of at each run ([exemple](https://github.com/louneskmt/ion/blob/docker-images/docker/ion-core/entrypoint.sh) of simple entrypoint), and to run the container more deterministically (less chance for the container to fail because of a possible build error).

2. **Persistent data**

What directories or files need to be persisted between sessions (i.e. saved to the host filesystem)? Is persisting `mongo` database and `ipfs` directory enough, or is there anything else I'm missing?

3. **Use of environment variables**

Dedicated issue: #189

Thanks!