update configurator advanced options

Author: tjhorner

docs/docs/02-user-manual/01-configuration/03-advanced.md

@@ -2,6 +2,14 @@
 
 This section includes more advanced or uncommon options.
 
+## API Server
+
+If you're self-hosting your own [Transit Tracker API server](../../03-advanced/api-server.md), you can enter its URL here. Make sure to include the full URL, including `http://` or `https://`.
+
 ## Display Orientation
 
-If you want to mount your Transit Tracker so that the USB-C port and buttons are on the left side instead of the right (i.e., if you have a short cable), you can flip the display orientation with this option. Flipping the orientation will also swap the order of the brightness control buttons to match.
+If you want to mount your Transit Tracker so that the USB-C port and buttons are on the left side instead of the right (i.e., if you have a short cable), you can flip the display orientation with this option. Flipping the orientation will also swap the order of the brightness control buttons to match.
+
+## Localization
+
+The Transit Tracker UI will show time units ("Now", "minutes", etc.) in English by default. You can customize these labels if you speak a different language.