use cargo-chef for faster docker builds

[Logan-Dang]

📜 Description

• Describe what changes are being made

  • Made a change to Dockerfile.backend to use cargo-chef for faster builds.
  • Made a change to docker-compose.yml, orval.config.ts to change how requests are made to the backend. This is necessary because during the prerender step, the frontend needs to make requests to http://backend:8080, but during development, it needs to make requests to http://localhost:8080.
  • Changed postinstall.ts to setup.ts to remove friction with setting API_URL.

• Describe how you tested these changes

1. docker compose watch
2. Website works as normal.