feat: add quickstart cmd with templates to run

[anistark]

Changes Made

• new cli command for quickstart templates
• supported templates: rag_eval, agent_evals, benchmark_llm, prompt_evals and workflow_eval

Template	Name	Description
rag_eval	RAG Evaluation	Evaluate a RAG system with custom metric
agent_evals	Agent Evaluation	Evaluate AI agents with structured metrics and workflows
benchmark_llm	LLM Benchmarking	Benchmark and compare different LLMs with datasets
prompt_evals	Prompt Evaluation	Evaluate and compare different prompt variations
workflow_eval	Workflow Evaluation	Evaluate complex LLM workflows and pipeline

Testing

How to Test

• Automated tests added/updated
• Manual testing steps:
  1. uv run ragas quickstart
  2. uv run ragas quickstart rag_eval
  3. uv run ragas quickstart rag_eval --output-dir ./my-project

[jjmachan]

overall this is great!
just a few questions