Merge branch 'docs-container-scanning-additional-ca-bundle' into 'master'

Docs for ADDITIONAL_CA_CERT_BUNDLE env var

See merge request gitlab-org/gitlab!27732

doc/user/application_security/container_scanning/index.md

@@ -183,6 +183,7 @@ using environment variables.
 | `CLAIR_DB_IMAGE`               | The Docker image name and tag for the [Postgres server hosting the vulnerabilities definitions](https://hub.docker.com/r/arminc/clair-db). It can be useful to override this value with a specific version, for example, to provide a consistent set of vulnerabilities for integration testing purposes, or to refer to a locally hosted vulnerabilities database for an on-premise air-gapped installation.                                                                                                                                                                                                                                                                                                                                                                      | `arminc/clair-db:latest`                                                                                        |
 | `CLAIR_DB_IMAGE_TAG`           | (**DEPRECATED - use `CLAIR_DB_IMAGE` instead**) The Docker image tag for the [Postgres server hosting the vulnerabilities definitions](https://hub.docker.com/r/arminc/clair-db). It can be useful to override this value with a specific version, for example, to provide a consistent set of vulnerabilities for integration testing purposes.                                                                                                                                                                                                                                                                                                                                                                                                                                   | `latest`                                                                                                        |
 | `DOCKERFILE_PATH`              | The path to the `Dockerfile` to be used for generating remediations. By default, the scanner will look for a file named `Dockerfile` in the root directory of the project, so this variable should only be configured if your `Dockerfile` is in a non-standard location, such as a subdirectory. See [Solutions for vulnerabilities](#solutions-for-vulnerabilities-auto-remediation) for more details.                                                                                                                                                                                                                                                                                                                                                                          | `Dockerfile`                                                                                                    |
+| `ADDITIONAL_CA_CERT_BUNDLE`   | Bundle of CA certs that you want to trust. | "" |
 
 ### Overriding the Container Scanning template