Add DEVELOPMENT_PLAN.md and update README.md

DEVELOPMENT_PLAN.md

@@ -0,0 +1,47 @@
+# YouTube Chat Webhook Listener (Version 2) - gRPC Implementation Plan
+
+This document outlines the detailed plan for implementing a robust, quota-friendly, open-source, and Linux-compatible solution for monitoring YouTube Live Chat by leveraging the recommended `liveChatMessages.streamList` gRPC endpoint.
+
+## Phase 1: gRPC Client Setup
+
+1.  **Install Dependencies:**
+    *   **Action:** Install `grpcio` and `grpcio-tools` Python packages.
+
+2.  **Obtain `.proto` File:**
+    *   **Action:** Locate and download the official Protocol Buffers (`.proto`) file that defines the `liveChatMessages.streamList` service.
+
+3.  **Generate Python Client Code:**
+    *   **Action:** Use `grpc_tools.protoc` to generate the Python client-side libraries from the `.proto` file.
+
+4.  **Develop gRPC Client:**
+    *   **Action:** Write a Python script to:
+        *   Establish a secure gRPC channel to the YouTube API endpoint.
+        *   Create a client stub for the `liveChatMessages.streamList` service.
+        *   Initiate the `StreamList` request to begin receiving messages.
+        *   Implement a loop to continuously process messages as they are pushed from the server.
+
+## Phase 2: Integration and Enhancements
+
+1.  **Integrate with Display Logic:**
+    *   **Action:** Adapt the existing `rich` display logic from `main.py` to consume messages received from the gRPC client instead of the polling mechanism.
+
+2.  **Error Handling & Resilience:**
+    *   **Action:** Implement robust error handling for gRPC connections, including automatic reconnection logic.
+    *   **Action:** Utilize `nextPageToken` (if provided by the gRPC stream) to resume receiving messages from where the connection was interrupted, preventing data loss.
+
+3.  **Configuration:**
+    *   **Action:** Externalize API keys, default video ID, and display preferences into a configuration file (e.g., `config.ini` or `config.json`).
+
+4.  **Enhance Display Features:**
+    *   **Action:** Implement a more sophisticated system to assign consistent, unique colors to each user.
+    *   **Action:** Improve emote rendering and potentially integrate with external emote services (e.g., BTTV, FrankerFaceZ) if feasible and compliant.
+    *   **Action:** Add options for message filtering (e.g., by user, keywords, message type).
+
+## Phase 3: Testing and Documentation
+
+1.  **Unit and Integration Tests:**
+    *   **Action:** Write comprehensive unit tests for the gRPC client, message processing, and display logic.
+    *   **Action:** Develop integration tests to ensure the end-to-end flow works correctly.
+
+2.  **Update Documentation:**
+    *   **Action:** Update the project's `README.md` with detailed usage instructions, setup guides, and explanations of the gRPC implementation.