feat: add Tooltip (to be implemented)

flexiui-core/src/commonMain/kotlin/com/highcapable/flexiui/window/Tooltip.kt

@@ -0,0 +1,26 @@
+/*
+ * Flexi UI - A flexible and useful UI component library.
+ * Copyright (C) 2019-2023 HighCapable
+ * https://github.com/BetterAndroid/FlexiUI
+ *
+ * Apache License Version 2.0
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * This file is created by fankes on 2023/12/1.
+ */
+@file:Suppress("unused")
+
+package com.highcapable.flexiui.window
+
+// TODO: To be implemented