Docs: Update Releases documentation to include creation from CI pipeline

doc/user/project/releases/index.md

@@ -79,6 +79,16 @@ To create a new release through the GitLab UI:
    [release notes](#release-notes-description), or [assets links](#links).
 1. Click **Create release**.
 
+### Create release from GitLab CI 
+
+> [Introduced](https://gitlab.com/gitlab-org/gitlab/-/merge_requests/19298) in GitLab 12.7.
+
+You can [create a release directly from the GitLab CI pipeline](../../../ci/yaml/README.md#release)
+by using a `release` node in the job definition.
+
+The release is created only if the job processes without error. If the Rails API returns an error
+during release creation, the release job fails.
+
 ### Schedule a future release
 
 > [Introduced](https://gitlab.com/gitlab-org/gitlab-foss/-/issues/38105) in GitLab 12.1.