QWindowkit 实现无边框，阴影支持系统边栏缩放等功能

一.感谢作者，QWindowkit 源码地址:

GitHub - stdware/qwindowkit: Cross-platform frameless window framework for Qt. Support Windows, macOS, Linux.

二.集成pro工程：

QT       += core gui

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

CONFIG += c++17

# You can make your code fail to compile if it uses deprecated APIs.
# In order to do so, uncomment the following line.
#DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000    # disables all the APIs deprecated before Qt 6.0.0

SOURCES += \
    main.cpp \