User Experience Improvements

[SatinWukerORIG]

Thank you for making this app! I believe that every rickroll developer appreciates your hard work!
However, as i use this software, i realized that some crucial enhancements should be made.

1. Support full screen
2. Introduction page right after opening the app.
   just like what vscode has:
   
3. An icon on the editor's banner:
   you can use the logo of Rickroll lang
   
   or the old logo:

Thank you! and I will also contribute to this project

[RedEnder666]

Thank you for your response!
I added resizing and fullscreen support today and yeah, i gonna add logo and main page later. =)