Summarized several one-line headings

Related to: https://gitlab.com/gitlab-org/gitlab/-/issues/358855

doc/user/infrastructure/clusters/connect/index.md

@@ -10,11 +10,6 @@ The [certificate-based Kubernetes integration with GitLab](../index.md)
 was [deprecated](https://gitlab.com/groups/gitlab-org/configure/-/epics/8)
 in GitLab 14.5. To connect your clusters, use the [GitLab agent](../../../clusters/agent/index.md).
-<!-- TBA: (We need to resolve https://gitlab.com/gitlab-org/gitlab/-/issues/343660 before adding this line)
-If you don't have a cluster yet, create one and connect it to GitLab through the agent.
-You can also create a new cluster from GitLab using [Infrastructure as Code](../../iac/index.md#create-a-new-cluster-through-iac).
--->
-
 ## Cluster levels (DEPRECATED)
 > [Deprecated](https://gitlab.com/groups/gitlab-org/configure/-/epics/8) in GitLab 14.5.

doc/user/infrastructure/iac/index.md

@@ -32,8 +32,7 @@ To get started, choose the template that best suits your needs:
 All templates:
-- Use the [GitLab-managed Terraform state](#gitlab-managed-terraform-state) as
-  the Terraform state storage backend.
+- Use the [GitLab-managed Terraform state](terraform_state.md) as the Terraform state storage backend.
 - Trigger four pipeline stages: `test`, `validate`, `build`, and `deploy`.
 - Run Terraform commands: `test`, `validate`, `plan`, and `plan-json`. It also runs the `apply` only on the default branch.
 - Run the [Terraform SAST scanner](../../application_security/iac_scanning/index.md#configure-iac-scanning-manually).
@@ -89,37 +88,19 @@ To use a Terraform template:
     # TF_ROOT: terraform/production
    ```
-1. (Optional) Override in your `.gitlab-ci.yml` file the attributes present
+1. Optional. Override in your `.gitlab-ci.yml` file the attributes present
 in the template you fetched to customize your configuration.
-## GitLab-managed Terraform state
-
-Use the [GitLab-managed Terraform state](terraform_state.md) to store state
-files in local storage or in a remote store of your choice.
-
-## Terraform module registry
-
-Use GitLab as a [Terraform module registry](../../packages/terraform_module_registry/index.md)
-to create and publish Terraform modules to a private registry.
-
-## Terraform integration in merge requests
-
-Use the [Terraform integration in merge requests](mr_integration.md)
-to collaborate on Terraform code changes and Infrastructure-as-Code
-workflows.
-
-## The GitLab Terraform provider
-
-The [GitLab Terraform provider](https://github.com/gitlabhq/terraform-provider-gitlab) is a Terraform plugin to facilitate
-managing of GitLab resources such as users, groups, and projects. It is released separately from GitLab
-and its documentation is available on [Terraform](https://registry.terraform.io/providers/gitlabhq/gitlab/latest/docs).
-
-## Create a new cluster through IaC
-
-- Learn how to [create a new cluster on Amazon Elastic Kubernetes Service (EKS)](../clusters/connect/new_eks_cluster.md).
-- Learn how to [create a new cluster on Google Kubernetes Engine (GKE)](../clusters/connect/new_gke_cluster.md).
-
 ## Related topics
-- [Terraform images](https://gitlab.com/gitlab-org/terraform-images).
-- [Troubleshooting](troubleshooting.md) issues with GitLab and Terraform.
+- View [the images that contain the `gitlab-terraform` shell script](https://gitlab.com/gitlab-org/terraform-images).
+- Use GitLab as a [Terraform module registry](../../packages/terraform_module_registry/index.md).
+- To store state files in local storage or in a remote store, use the [GitLab-managed Terraform state](terraform_state.md).
+- To collaborate on Terraform code changes and Infrastructure-as-Code workflows, use the
+  [Terraform integration in merge requests](mr_integration.md).
+- To manage GitLab resources like users, groups, and projects, use the
+  [GitLab Terraform provider](https://github.com/gitlabhq/terraform-provider-gitlab). It is released separately from GitLab
+  and its documentation is available on [the Terraform docs site](https://registry.terraform.io/providers/gitlabhq/gitlab/latest/docs).
+- [Create a new cluster on Amazon Elastic Kubernetes Service (EKS)](../clusters/connect/new_eks_cluster.md).
+- [Create a new cluster on Google Kubernetes Engine (GKE)](../clusters/connect/new_gke_cluster.md).
+- [Troubleshoot](troubleshooting.md) issues with GitLab and Terraform.

doc/user/project/clusters/add_eks_clusters.md

@@ -10,7 +10,7 @@ info: To determine the technical writer assigned to the Stage/Group associated w
 > - [Deprecated](https://gitlab.com/groups/gitlab-org/configure/-/epics/8) in GitLab 14.5.
 WARNING:
-This feature was deprecated in GitLab 14.5. Use [Infrastructure as Code](../../infrastructure/iac/index.md#create-a-new-cluster-through-iac)
+This feature was deprecated in GitLab 14.5. Use [Infrastructure as Code](../../infrastructure/iac/index.md)
 to create new clusters.
 Through GitLab, you can create new clusters and add existing clusters hosted on Amazon Elastic
@@ -23,7 +23,7 @@ use the [GitLab agent](../../clusters/agent/index.md).
 ## Create a new EKS cluster
-To create a new cluster from GitLab, use [Infrastructure as Code](../../infrastructure/iac/index.md#create-a-new-cluster-through-iac).
+To create a new cluster from GitLab, use [Infrastructure as Code](../../infrastructure/iac/index.md).
 ### How to create a new cluster on EKS through cluster certificates (DEPRECATED)

doc/user/project/clusters/add_remove_clusters.md

@@ -10,7 +10,7 @@ info: To determine the technical writer assigned to the Stage/Group associated w
 WARNING:
 This feature was [deprecated](https://gitlab.com/gitlab-org/gitlab/-/issues/327908) in GitLab 14.0.
-To create and manage a new cluster use [Infrastructure as Code](../../infrastructure/iac/index.md#create-a-new-cluster-through-iac).
+To create and manage a new cluster use [Infrastructure as Code](../../infrastructure/iac/index.md).
 ## Disable a cluster