Reorganize Matrix documentation

content/docs/infrastructure/matrix/_index.md

@@ -48,13 +48,17 @@ the following syntax for a room alias:
 
 [^3]: [Internet Relay Chat (IRC)](https://en.wikipedia.org/wiki/Intenet_Relay_Chat) in the Wikipedia
 
-There's a web service provided by the Matrix.org Foundation for linking users,
-rooms and messages, which can ease onboarding:
-
-{{< cards >}}
-  {{< card icon="external-link" link="https://matrix.to/" title="Matrix.to" >}}
-{{< /cards >}}
-
+There's a web service at https://matrix.to/ provided by the Matrix.org
+Foundation for linking users, rooms and messages, which can ease onboarding.
 Additionally, https://view.matrix.org lists rooms that can be joined without 
 invitation and provides information such as member count and topic. Following
-their links displays a history of messages in this room.
+their links displays a history of messages in this room.
+
+## Guides
+
+{{< cards >}}
+
+{{< card link="public-server-list" title="Public server list" icon="login" >}}
+{{< card link="synapse" title="Synapse" icon="server" >}}
+
+{{< /cards >}}