Add GitLab 15.3 changelog

@Normo Could you please check the Changelog entry for GitLab 15.3. Thanks :)

docs/software/gitlab/changelog.md

@@ -7,7 +7,7 @@ title: Changelog
 * Update GitLab to version 15.3
     * [Create tasks in issues][15-3-tasks]
     * [Submit merge request review with summary comment][15-3-summary]
-    * All details are availabke in the [Release Post][15-3-release-post]
+    * All details are available in the [Release Post][15-3-release-post]
 
 [15-3-tasks]: https://about.gitlab.com/releases/2022/08/22/gitlab-15-3-released/#create-tasks-in-issues
 [15-3-summary]: https://about.gitlab.com/releases/2022/08/22/gitlab-15-3-released/#submit-merge-request-review-with-summary-comment