Merge branch 'kenneth-clarify-action-include-already-exists' into 'master'

Clarify actions if `include` line already exists

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/143449



Merged-by: Russell Dickenson <rdickenson@gitlab.com>
Approved-by: Russell Dickenson <rdickenson@gitlab.com>
Co-authored-by: Kenneth Chu <ksiuhengchu@gitlab.com>

doc/user/application_security/dast/proxy-based.md

@@ -107,7 +107,8 @@ To include the DAST template:
 
 1. On the left sidebar, select **Search or go to** and find your project.
 1. Select **Build > Pipeline editor**.
-1. Copy and paste the following to the bottom of the `.gitlab-ci.yml` file.
+1. Copy and paste the following to the bottom of the `.gitlab-ci.yml` file. If an `include` line
+   already exists, add only the `template` line below it.
 
    To use the DAST stable template:
 

doc/user/application_security/iac_scanning/index.md

@@ -42,7 +42,8 @@ To enable IaC scanning of a project:
 
 1. On the left sidebar, select **Search or go to** and find your project.
 1. Select **Build > Pipeline editor**.
-1. Copy and paste the following to the bottom of the `.gitlab-ci.yml` file.
+1. Copy and paste the following to the bottom of the `.gitlab-ci.yml` file. If an `include` line
+   already exists, add only the `template` line below it.
 
    ```yaml
    include:

doc/user/application_security/sast/index.md

@@ -315,7 +315,8 @@ To enable SAST, you [include](../../../ci/yaml/index.md#includetemplate)
 the [`SAST.gitlab-ci.yml` template](https://gitlab.com/gitlab-org/gitlab/-/blob/master/lib/gitlab/ci/templates/Jobs/SAST.gitlab-ci.yml).
 The template is provided as a part of your GitLab installation.
 
-Add the following to your `.gitlab-ci.yml` file:
+Copy and paste the following to the bottom of the `.gitlab-ci.yml` file. If an `include` line
+already exists, add only the `template` line below it.
 
 ```yaml
 include:

doc/user/application_security/secret_detection/index.md

@@ -144,7 +144,8 @@ your GitLab CI/CD configuration file is complex.
 
 1. On the left sidebar, select **Search or go to** and find your project.
 1. Select **Build > Pipeline editor**.
-1. Copy and paste the following to the bottom of the `.gitlab-ci.yml` file:
+1. Copy and paste the following to the bottom of the `.gitlab-ci.yml` file. If an `include` line
+   already exists, add only the `template` line below it.
 
    ```yaml
    include: