docs: Add instructions for launching service from source (#619)

This commit includes detailed steps for setting up and launching the
service directly from the source code. It covers cloning the repository,
setting up a virtual environment, configuring environment variables, and
starting the service using Docker. This update ensures that developers
have clear guidance on how to get the service running in a development
environment.

### What problem does this PR solve?

_Briefly describe what this PR aims to solve. Include background context
that will help reviewers understand the purpose of the PR._

### Type of change
- [x] Documentation Update