Experiment with creating Mac port

[Hexman768]

Description

• I think we should at least attempt to create a Mac port of Notepad#.

Technical Investigation

• This would involve using Mono to actually create the port, and probably adding some preprocessor conditional statements to use different code depending on the operating system of the host machine.
• Here is a link to an article explaining the process of create a Mac port of an existing Windows Forms application: https://www.mono-project.com/docs/gui/winforms/porting-winforms-applications/.