docs: Matrix chat on home page + self-serve federated MXID in getting-started

README.md

@@ -20,6 +20,7 @@ funded through our [Open Collective](https://opencollective.com/inference-cooper
 
 - **Website:** https://inference.coop
 - **AI Chat:** https://chat.inference.coop
+- **Matrix chat:** https://matrix.inference.coop
 - **Member Dashboard:** https://dashboard.inference.coop
 - **Governance forum:** https://forum.inference.coop
 - **Source code:** https://git.inference.coop

getting-started.md

@@ -69,8 +69,10 @@ privacy, and direction happen on our **Loomio forum**:
   - **FluffyChat, Cinny, SchildiChat** or any other client: look for the "custom homeserver"
     / "other server" option in the client's login screen and enter the same address.
   - Your co-op account and your existing Matrix account on another server (e.g.
-    matrix.org or a personal homeserver) are separate identities — keep whichever you
-    like for co-op rooms; both can join. Invites go to your co-op account by default.
+    matrix.org or a personal homeserver) are separate identities. If you'd
+    rather use an existing account for co-op rooms, set it on your
+    [dashboard](https://dashboard.inference.coop) under **Matrix chat** (one
+    extra account) — invitations will go there instead. Both work either way.
 - See the [Charter](charter.md) for how governance is structured.
 - See [Open questions](open-questions.md) for the decisions currently on the table.