Remove outdated demo repos (#2387)

Author: ZIJ

docs/ce/getting-started/with-terraform.mdx

@@ -5,7 +5,7 @@ title: "With Terraform"
 In this tutorial, you will set up Digger to automate terraform pull requests using Github Actions
 
 **Prerequisites**
-- A GitHub repository with valid terraform code, don't have one? see [here](#demo-repositories)
+- A GitHub repository with valid terraform code. Don't have one? see [Example repo](https://github.com/diggerhq/quickstart-actions-aws)
 - Your cloud provider credentials:
   - For AWS: [Hashicorp's AWS tutorial](https://developer.hashicorp.com/terraform/tutorials/aws-get-started/aws-build)
   - For GCP: [Hashicorp's GCP tutorial](https://developer.hashicorp.com/terraform/tutorials/gcp-get-started/google-cloud-platform-build)
@@ -284,10 +284,4 @@ Then you can add a comment like `digger apply` and shortly after apply output wi
 </Step>
 </Steps>
 
-## Demo repositories
-
-- [AWS demo repo](https://github.com/diggerhq/quickstart-actions-aws)
-- [GCP demo repo](https://github.com/diggerhq/demo-conftest-gcp/)
-- [Azure demo repo](https://github.com/diggerhq/azure-onboarding-test)
-