Suggestion: define WEIGHTS disk location in only one place so it can be user-customized

[julien-c]

(for people who want to run outside of Docker for instance)

[snxraven]

You can customize this location during the docker run command.

This is the default command provided which uses docker volumes:

docker run -d \
         -v weights:/usr/src/app/weights -v datadb:/data/db/ \
         -p 8008:8008 ghcr.io/nsarrazin/serge:latest

This can be changed to use a local directory like so:

docker run -d \
         -v /path/to/weights/on/host/:/usr/src/app/weights -v datadb:/data/db/ \
         -p 8008:8008 ghcr.io/nsarrazin/serge:latest

[nsarrazin]

I do think there's a few things that need to be made into optional environment variables indeed, I heard a similar request regarding the redis server, from people who already have an instance running and don't want to run an instance specifically for serge.

So I will try to make things a bit more customizable. (location of weights, location of the redis snapshot to disk, network address of the redis server)

This should be fairly easy to setup with the BaseSettings class from pydantic. There's already a few pieces in place in api/src/serge/models/settings.py