added config file

templates/config.json.j2

@@ -0,0 +1,17 @@
+#--Configuration file for element-web -----#
+
+{
+  "default_server_config": {
+    "m.homeserver": {
+      "base_url": "https://{{ matrix_domain1 }}",
+      "server_name": "{{ matrix_domain1 }}"
+    }
+  },
+  "disable_custom_urls": true,
+  "disable_guests": true,
+  "brand": "{{ element_brand }}",
+  "default_theme": "dark",
+  "roomDirectory": {
+    "servers": ["{{ matrix_domain1 }}"]
+  }
+}