docs: Add release notes (fixes #4)

.gitlab-ci.yml

 variables:
+  PROJECT_ID: ${CI_PROJECT_ID}
   ROLE: ${CI_PROJECT_NAME}
   BRANCH: ${CI_COMMIT_REF_NAME}
   TAG: ${CI_COMMIT_TAG}

RELEASES.md

+# Releases
+
+## 0.2.x
+
+- Support for Ubuntu 22.04 LTS added.
+
+## 0.1.x
+
+- Initial role implementation.