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docs/custom-menu.md

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+# Custom Menu Items
+
+You can add custom menu items to the main menu (sidebar) by providing a `menu` array in the config.
+This is useful for adding links to external sites or other pages in your documentation, like a support page or internal wiki.
+
+## Configuration
+
+The examples below contain the configuration settings to add a link to the [Synapse Admin issues](https://github.com/etke.cc/synapse-admin/issues).
+
+Each `menu` item can contain the following fields:
+
+* `label` (required): The text to display in the menu.
+* `icon` (optional): The icon to display next to the label, one of the [../src/components/icons.ts] icons, otherwise a
+default icon will be used.
+* `url` (required): The URL to navigate to when the menu item is clicked.
+
+### config.json
+
+```json
+{
+  "menu": [
+    {
+      "label": "Contact support",
+      "icon": "SupportAgent",
+      "url": "https://github.com/etkecc/synapse-admin/issues"
+    }
+  ]
+}
+```
+
+### `/.well-known/matrix/client`
+
+```json
+{
+  "cc.etke.synapse-admin": {
+    "menu": [
+      {
+        "label": "Contact support",
+        "icon": "SupportAgent",
+        "url": "https://github.com/etkecc/synapse-admin/issues"
+      }
+    ]
+  }
+}
+```