[Feature]: Provide a starter template for running a basic agent workflow

[anjalimahajan2603]

🔖 Feature description

To help new developers get up and running quickly, add a minimal example workflow:

Example directory:
└── hello-agent/
├── workflow.yaml
└── README.md

Contents:

• workflow.yaml: Basic workflow that sends a greeting prompt.
• README.md: Instructions for running via CLI (e.g., julep run examples/hello-agent/workflow.yaml)

This offers a tangible starting point for newcomers to test functionality and explore modifications.

🎤 Why is this feature needed ?

Currently, new contributors and users face a steep learning curve when trying to understand and run Julep workflows. A ready-to-use "Hello Agent" example would:

• Lower the entry barrier for first-time contributors
• Provide an immediate hands-on demo of Julep’s workflow capabilities
• Serve as a foundation for testing and extending more complex workflows

✌️ How do you aim to achieve this?

• Create a new examples/hello-agent/ directory
• Add workflow.yaml containing a minimal agent that greets the user
• Write README.md with step-by-step instructions to run it via CLI
• Optionally include comments in the YAML file explaining each section

👀 Have you searched issues and PRs to see if this feature request has been raised before?

• I checked and didn't find similar issue