agents: continued

[elithrar]

Proposed changes

• Adds a new Quickstart that provides a shorter guide + uses a new C3 template - e.g. npm create cloudflare@latest my-agent -- --type=agent to get started with the basics
• Adds a new guide (?) that shows how to add Agent powers to an existing Workers project
• Add new /agents/concepts/patterns doc to show typical patterns? Single shot, long running, agent-per-task, co-ordinator pattern (agents/workflows)
• Pricing: update DO pricing to talk more about concurrency, how 1 vs 100 vs 1000 requests costs the same in terms of GB-s, and that a DO can run for tens of minutes to hours + persist + reload state - e.g. for long running LLM calls or prompt chaining
• Add a model routing page at /agents/api-reference/model-routing/

Follow up from #20339

[kodster28]

Going to close this out as I think the major work associated has either been done or moved to other channels