fix: Include commands to create Spot Service Linked Role

## Expected Behavior

All of the steps necessary to run Karpenter in a new account should be outlined, including creating the EC2 Spot Service Linked Role.

https://karpenter.sh/v0.17.0/getting-started/getting-started-with-terraform/#create-the-ec2-spot-service-linked-role

## Actual Behavior

This step is omitted, which will cause the Karpenter content to break in accounts without the role.

Error in CloudTrail logs:

`The provided credentials do not have permission to create the service-linked role for EC2 Spot Instances.`

## Steps to Reproduce the Problem

Run the Karpenter scenarios either manually or using the automation. Ensure that the Spot Service Linked Role is not present in the account.