Add link to release notes to docs

docs/src/.vuepress/config.js

@@ -36,6 +36,7 @@ module.exports = {
 					children: [
 						"",
 						"help/",
+						"releases/",
 						"contribute/"
 					]
 				},

docs/src/users/releases/README.md

@@ -0,0 +1,7 @@
+# Release notes
+
+If you would like to be informed about changes, bugfixes and new features on FacilMap, have a look at the [release notes](https://github.com/FacilMap/facilmap/releases) on GitHub.
+
+To receive notifications about new releases, there are multiple options:
+* Use a newsreader to subscribe to the [Atom feed](https://github.com/FacilMap/facilmap/releases.atom)
+* To be notified by e-mail, register on GitHub and watch the facilmap repository. On the top right, click “Watch”, then “Custom” and then select “Releases”.