Add CLI examples for Amazon Macie2 core commands

[sushilk123]

Add CLI examples for Amazon Macie2 core commands

Description

Adds missing CLI examples for Amazon Macie2 security service commands to improve documentation coverage.

Changes

• Add enable-macie example showing basic enablement and custom configuration options
• Add get-findings example showing security finding retrieval and filtering capabilities
• Add create-classification-job example for one-time and scheduled data classification jobs
• Improves documentation coverage for Amazon Macie2 service from 1 to 4 examples

Testing

Examples follow existing AWS CLI documentation format and provide realistic use cases for essential Macie2 security workflows including service setup, finding analysis, and data classification.