Migrate caddy.json to nix and setup matrix well-known
diff --git a/modules/caddy/coded.codes/.well-known/matrix b/modules/caddy/coded.codes/.well-known/matrix
new file mode 100644
index 0000000..891445a
--- /dev/null
+++ b/modules/caddy/coded.codes/.well-known/matrix
@@ -0,0 +1,6 @@
+{
+  "m.server": "matrix-backend.coded.codes:443",
+  "m.homeserver": {
+    "base_url": "https://matrix-backend.coded.codes:443"
+  }
+}