Update many files.

Add some description about this project, and now it has a simple UI (made with Qt)

If you don't specify the mode of (interface?) the UI. Launcher will show a crude window that lets you
 select a mode to start the (real) launcher.

Test version data fetching functions. Looks great.

core_lib/qt/hack.py

@@ -0,0 +1,10 @@
+from PySide6.QtGui import QScreen
+from PySide6.QtWidgets import QMainWindow, QApplication
+
+
+def move_window_to_center(window: QMainWindow):
+    main_screen = QApplication.primaryScreen()
+    center = QScreen.availableGeometry(main_screen).center()
+    geometry = window.frameGeometry()
+    geometry.moveCenter(center)
+    window.move(geometry.topLeft())