Update actionlib.md file (#1239)

This PR completely rewrites the `actionlib.md` tutorial file to provide comprehensive documentation for ROS 2 actions in rclnodejs. The update transforms a deprecated, minimal tutorial into a modern, detailed guide covering all aspects of action implementation.

Key changes include:
- Complete replacement of deprecated actionlib content with ROS 2 actions documentation
- Addition of detailed code examples for both action servers and clients
- Introduction of advanced features like goal cancellation and multiple goal handling


Fix: #1238

Author: minggangw