Create Snippets for `aws_rds`

[sameeramin]

We need to create code snippets for AWS RDS (Relational Database Service) resources in our VSCode extension. This includes common patterns and configurations used with RDS, such as creating database instances, defining parameter groups, and configuring security groups. Additionally, we need to update the documentation to include information on how to use these new snippets effectively.

Tasks:

• Create code snippets for common AWS RDS resources and configurations.
• Update the documentation to include usage instructions and examples for the new RDS snippets.