docs: update README to include warning event notification for withdrawal instances

Change description

Updated README documentation to include information about warning event notifications for withdrawal instances. Added documentation showing how to listen for warning events that don't require remounting the component instance using withdrawal.on('warning', error => ...).

Type of change

• Bug fix (fixes an issue)
• New feature (adds functionality)
• Chore (task that not add a new functionality or fix an issue)

Related issues

Checklists

Development

• Lint rules pass locally
• Application changes have been tested thoroughly
• Docker Image was build correctly

Security

• Security impact of change has been considered
• Code follows company security practices and guidelines

Network

• Changes to network configurations have been reviewed
• Any newly exposed public endpoints or data have gone through security review

Code review

• Merge request has a descriptive title and context useful to a reviewer. Screenshots or screencasts are attached as necessary
• "Ready for review" label attached and reviewers assigned
• Changes have been reviewed by at least one other contributor