Pygubu

* Fix for issues 251 and 253
* Drop support for python 3.6 and 3.7 (was already not working)

* Fix issue with project path with windows junction link. refs 249
* Fix code template error.
* Fix error when "live" updating preview properties
* Added new example for EditableTreeview

* Add option to reset window layout. (244 jrezai)

* New UI Layout. Removed code generation Tab.
* New project settings dialog.
* Cleaned designer settings dialog.

* Update to support customtkinter 5.2.2

* Customize open file dialog on Gnu/Linux.
* New format for ttk style definition file. alejandroautalan/pygubu-designer204, alejandroautalan/pygubu-designer211
* New settings to auto generate code in Code Tab. (BloodyRain2k)
* Fix scrolling in toolbar frame (BloodyRain2k)
* New option to render widget palette as a single section widget toolbar.
Changes the widget toolbar to contain all chosen widgets instead of grouping them with tabs.
Useful for wide monitors. (BloodyRain2k)
* Type hints for tk variables in code generation. (BloodyRain2k)
* Add template code to center window at start. (BloodyRain2k)
* New Vietnamese translation for README.md (lebao3105)
* Update Chinese Translation (littlewhitecloud)