i18n: add Ukrainian translation (#76)

Author: TheDeVerO

src/i18n/Engine.cpp

@@ -105,6 +105,9 @@ void I18n::initEngine() {
 
     // tr_TR (Turkish)
     engine.registerEntry("tr_TR", TXT_KEY_SEARCH_SOMETHING, "Ara...");
+    
+    // uk_UA (Ukrainian)
+    engine.registerEntry("uk_UA", TXT_KEY_SEARCH_SOMETHING, "Пошук...");
 
     // vi_VN (Vietnamese)
     engine.registerEntry("vi_VN", TXT_KEY_SEARCH_SOMETHING, "Tìm kiếm...");