Update README.md

[eyapene]

Description

Add an example of deleting a specific deployment with Terraform

Related Issues

Motivation and Context

Customers ask how to delete a specific deployment with Terraform

How Has This Been Tested?

Types of Changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Refactoring (improves code quality but has no user-facing effect)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation

Readiness Checklist

• My code follows the code style of this project
• My change requires a change to the documentation
• I have updated the documentation accordingly
• I have added tests to cover my changes
• All new and existing tests passed

[tobio]

There's nothing provider specific around resource targeting, IMO we should be pointing customers to the TF documentation for how to do this rather than re-inventing the wheel here.