added git date to copyright

mkdocs.yml

@@ -1,6 +1,6 @@
 site_name: 'mailcow: dockerized documentation'
 site_url: https://mailcow.github.io/mailcow-dockerized-docs/
-copyright: "Copyright &copy; 2022 Servercow Team & Community<br>Revision: 2"
+copyright: "Copyright &copy; 2022 Servercow Team & Community <br>Last Updated: {{ git_revision_date }}"
 repo_name: mailcow/mailcow-dockerized
 repo_url: https://github.com/mailcow/mailcow-dockerized
 edit_uri: ../mailcow-dockerized-docs/edit/master/docs/

requirements.txt

@@ -2,3 +2,4 @@ mkdocs-material>=8.1.8
 mkdocs-redirects>=1.0.3
 pygments>=2.11.2
 mkdocs-static-i18n>=0.18
+mkdocs-git-revision-date-plugin>=0.3.1