Make the proxy settings configurable

[GreenTeaLeaf-hubble]

This PR makes the development proxy configurable via ENV variables and/or a config file.

Examples

~/.bashrc

export TRAEFIK_VERSION=v3.1
export TRAEFIK_DASH_PORT=3000
export DEVELOPMENT_PROXY_CONFIG_HOME=$XDG_CONFIG_HOME/development-proxy

~/.development-proxy/proxy-config.yml

traefik_version: v3.1
dashboard_port: 3000
entrypoints:
  postgresql: 5432
  zendserver: 10081

[rick-nu]

Oof, I think I'm missing a lot of context why you would want to do this?

The idea of the shared development proxy, is that you have a single, generalized way of connecting to your local containers to a local domain.

1. Can you explain why you want to make the version configurable, versus just bumping the version for everyone of required
2. I see you've used another external container to generate the config file, I'm not a fan of forcing other containers to run on user system other than just the proxy itself (even if its a run once action)
3. The readability of the script degraded a lot, making it feel less trustworthy for a developer to trust it in their project/system. Then again I might be missing why we would need this addition