keyboard: add new keys to schema

The stated schema-default for useLocale1 is not entirely correct,
since the code checks for X11 vs. Wayland to determine what the
default should be.

src/modules/keyboard/keyboard.schema.yaml

@@ -9,4 +9,6 @@ properties:
     xOrgConfFileName: { type: string }
     convertedKeymapPath: { type: string }
     writeEtcDefaultKeyboard: { type: boolean, default: true }
+    useLocale1: { type: boolean, default: false }
+    guessLayout: { type: boolean, default: true }
 required: [ xOrgConfFileName, convertedKeymapPath ]