Initial commit: OpenRouter Python SDK

Auto-generated Python SDK for OpenRouter API, providing comprehensive client library with:
- Chat completions and streaming support
- Embeddings API
- Model and provider information
- API key management
- Analytics and usage tracking
- OAuth authentication flows
- Full type hints and error handling

docs/models/message.md

@@ -0,0 +1,35 @@
+# Message
+
+
+## Supported Types
+
+### `models.SystemMessage`
+
+```python
+value: models.SystemMessage = /* values here */
+```
+
+### `models.UserMessage`
+
+```python
+value: models.UserMessage = /* values here */
+```
+
+### `models.MessageDeveloper`
+
+```python
+value: models.MessageDeveloper = /* values here */
+```
+
+### `models.AssistantMessage`
+
+```python
+value: models.AssistantMessage = /* values here */
+```
+
+### `models.ToolResponseMessage`
+
+```python
+value: models.ToolResponseMessage = /* values here */
+```
+