and initial page for mastodon too

Author: tswfi

src/SUMMARY.md

@@ -20,6 +20,7 @@
     - [Whatsapp](./matrix/whatsapp.md)
     - [Hookshot](./matrix/hookshot.md)
   - [Peertube](./services/peertube.md)
+  - [Mastodon](./services/mastodon.md)
 - [Sysops](./sysops/README.md)
   - [Upcloud](./sysops/upcloud.md)
     - [Server admin minutes](./sysops/upcloud/server-admin-minutes.md)

src/services/mastodon.md

@@ -0,0 +1,7 @@
+# Mastodon
+
+Hacklab runs their own [Mastodon](https://github.com/mastodon/mastodon) instance too.
+
+You can find it here [some.hacklab.fi](https://some.hacklab.fi)
+
+SSO login does not work yet!