docs: 更新 lighter-python-main 文档，添加示例代码和 API 说明，重构部分内容以提高可读性

docs/lighter/lighter-python-main/examples/ws_async.py

@@ -0,0 +1,24 @@
+import json
+import logging
+import asyncio
+import lighter
+
+logging.basicConfig(level=logging.INFO)
+
+
+def on_order_book_update(market_id, order_book):
+    logging.info(f"Order book {market_id}:\n{json.dumps(order_book, indent=2)}")
+
+
+def on_account_update(account_id, account):
+    logging.info(f"Account {account_id}:\n{json.dumps(account, indent=2)}")
+
+
+client = lighter.WsClient(
+    order_book_ids=[0, 1],
+    account_ids=[1, 2],
+    on_order_book_update=on_order_book_update,
+    on_account_update=on_account_update,
+)
+
+asyncio.run(client.run_async())