Initialized openttd-client repo

lib/openttd/README.md

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+# Internal Package: openttd
+
+This directory contains the core implementation of the OpenTTD network client.
+
+## Modules
+
+-   **`__init__.py`**: Exposes the high-level `OpenTTDClient` API.
+-   **`client.py`**: Implementation of the `OpenTTDClient` class. Manages the connection lifecycle, PAKE state, map synchronization, and keep-alive.
+-   **`protocol.py`**: Implementation of the `OpenTTDProtocol` class. Handles low-level binary packet serialization, AEAD stream encryption, and static packet parsing.
+
+## Design Goals
+1.  **Encapsulation:** The user should never need to manually handle bytes or encryption keys.
+2.  **Robustness:** Gracefully handle server errors and unknown packet types.
+3.  **Efficiency:** Use `asyncio` for non-blocking I/O and `monocypher` for fast cryptographic operations.