Settings has a Language row, for choosing Gearslip's language

Android 13 and later already let you pick it, but only from the
system's app settings, which few people find (#51).

gearslip/src/main/res/values-cs/strings.xml

@@ -847,4 +847,6 @@
     <string name="places_finding">Hledám…</string>
     <string name="places_not_found">Gearslip nenašel vaši polohu. Zkontrolujte, že je poloha zapnutá.</string>
     <string name="places_clear">Vymazat</string>
+    <string name="settings_language">Jazyk</string>
+    <string name="settings_language_phone">Stejný jako v telefonu</string>
 </resources>