Add versioning note to release notes

.gitlab/release-template.md

@@ -30,3 +30,9 @@ $AVAILABLE_OPENTOFU_VERSIONS
 This release deployed the following `gitlab-opentofu` images:
 
 $AVAILABLE_IMAGES
+
+> **Note:**
+> When using the component with the inputs `version` and `opentofu_version`,
+> then the image tag is constructed with the following pattern:
+> `<version>-opentofu<opentofu_version>`
+> Read more about versioning and releases [here](README.md#releases-versioning).