better signup disable

documentation/docs/Configuration/_category_.json

@@ -0,0 +1,8 @@
+{
+  "label": "Configuration ⚙️",
+  "position": 3,
+  "link": {
+    "type": "generated-index",
+    "description": "Options for AdventureLog settings."
+  }
+}

documentation/docs/Configuration/disable_registration.md

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+---
+sidebar_position: 1
+---
+
+# Disable Registration
+
+To disable registration, you can set the following variable in your docker-compose.yml under the server service:
+
+```yaml
+environment:
+  - DISABLE_REGISTRATION=True
+```