docs(blog): add 'Now you're thinking with Agents' blog post

[Tehsmash]

Summary

• Adds a new Portal-themed blog post: Now you're thinking with Agents
• Makes the case for deploying small agents co-located with remote resources (Kubernetes clusters, VMs, databases) and communicating agent-to-agent over A2A/SLIM, rather than exposing raw APIs or credentials to a central agent
• Covers the old mental model, the agent-native pattern with diagrams, two concrete examples (Kubernetes and VM configuration), enabling technologies (A2A + SLIM), properties of the pattern, and a "things to consider" section covering authorization, security boundaries, auditability, and operational overhead

[github-actions]

Blog preview

Preview deployed to: https://blogs.agntcy.org/drafts/feat-thinking-with-agents-blog/

Last updated: commit 5b30d73be25fa3dfd239c4a4895152f1584974af

[micpapal]

I like this post. It is probably not as technical as the others but it still gives a good idea on when and how SLIM can be used, so I think it is a good fit