Revert "docs:Update README.md" (#451)

Reverts #419

Author: holtskinner

README.md

@@ -29,7 +29,7 @@ Watch [this demo video](https://storage.googleapis.com/gweb-developer-goog-blog-
 
 The Agent2Agent (A2A) protocol facilitates communication between independent AI agents. Here are the core concepts:
 
-- **Agent Card:** A public metadata file (usually at `./well-known/agent.json`) describing an agent's capabilities, skills, endpoint URL, and authentication requirements. Clients use this for discovery.
+- **Agent Card:** A public metadata file (usually at `/.well-known/agent.json`) describing an agent's capabilities, skills, endpoint URL, and authentication requirements. Clients use this for discovery.
 - **A2A Server:** An agent exposing an HTTP endpoint that implements the A2A protocol methods (defined in the [json specification](/specification)). It receives requests and manages task execution.
 - **A2A Client:** An application or another agent that consumes A2A services. It sends requests (like `tasks/send`) to an A2A Server's URL.
 - **Task:** The central unit of work. A client initiates a task by sending a message (`tasks/send` or `tasks/sendSubscribe`). Tasks have unique IDs and progress through states (`submitted`, `working`, `input-required`, `completed`, `failed`, `canceled`).