Merge branch '116-explain-the-release-tagging-convention' into 'master'

Resolve "Explain the release/tagging convention"

Closes #116

See merge request https://gitlab.com/gitlab-org/terraform-images/-/merge_requests/231



Merged-by: Tiger Watson <twatson@gitlab.com>
Approved-by: Tiger Watson <twatson@gitlab.com>
Co-authored-by: Timo Furrer <tfurrer@gitlab.com>

README.md

@@ -77,3 +77,4 @@ the conventions of [Conventional Commits (v1.0.0)](https://www.conventionalcommi
 # Release
 
 Currently we release three versions of this image to support the last three stable major versions of Terraform. 
+The image versioning is documented [here](https://docs.gitlab.com/ee/user/infrastructure/iac/gitlab_terraform_helpers.html#terraform-images).
\ No newline at end of file