Tech debt: Improve documentation of Event model fields in EventBridge Model

[leandrodamascena]

Use case

Original issue: #5475

improve EventBridge model with description and examples

Solution/User Experience

improve EventBridge model with description and examples

Alternative solutions

Acknowledgment

• This feature request meets Powertools for AWS Lambda (Python) Tenets
• Should this be considered in other Powertools for AWS Lambda languages? i.e. Java, TypeScript, and .NET