docs(plugin): add guide to log strings for debugging

en/plugins/best-practice/how-to-print-strings-to-logs-for-debugging.mdx

@@ -0,0 +1,39 @@
+---
+title: Outputting Logs for Development and Debugging
+---
+
+As a plugin developer, you may want to print arbitrary strings to logs during plugin processing for development or debugging purposes.
+
+For this purpose, the plugin SDK implements a handler for Python's standard `logging` library. By using this, you can output any string to both the **standard output during remote debugging** and the **plugin daemon container logs** (community edition only).
+
+## Sample
+
+Import `plugin_logger_handler` and add it to your logger as a handler. Below is a sample code for a tool plugin.
+
+```python
+from collections.abc import Generator
+from typing import Any
+from dify_plugin import Tool
+from dify_plugin.entities.tool import ToolInvokeMessage
+
+
+# Import logging and custom handler
+import logging
+from dify_plugin.config.logger_format import plugin_logger_handler
+
+# Set up logging with the custom handler
+logger = logging.getLogger(__name__)
+logger.setLevel(logging.INFO)
+logger.addHandler(plugin_logger_handler)
+
+
+class LoggerDemoTool(Tool):
+    def _invoke(self, tool_parameters: dict[str, Any]) -> Generator[ToolInvokeMessage]:
+
+        # Log messages with different severity levels
+        logger.info("This is a INFO log message.")
+        logger.warning("This is a WARNING log message.")
+        logger.error("This is a ERROR log message.")
+
+        yield self.create_text_message("Hello, Dify!")
+```