Support config default window size

[yeliex]

Is your feature request related to a problem? Please describe.
Currently, if window enters full-screen and exists, the window size renders as the max size(but not full-screen). So users should resize it manually.

Describe the solution you'd like

• Support config default size(cols and lines like Mac default Terminal app), every time app lunch displays in the preferenced cols and lines
• Restore window layout after exit app or exit full-screen

[Jiwon Choi]

Could you provide images of the issue for better understanding?