added shortcut ctrl+q for quit and quit the app when using the Windows Close button

[mslourens]

Fixes #997

Changes:

• added a shortcut (like mentioned in the comments of the issue) CTRL/CMD+Q to quit the app.
• close the app (instead of minimize) when clicking the close button (could be changed in a setting in the future).

[kazup01]

Hi @mslourens , could you fix CI error?

[mslourens]

I am not sure why CI failed with the error message:

An error occurred while generating the build script.

Can somebody who knows the build process have a look? I just fixed the lint warnings generated by my previous change.

[kazup01]

Hi @mslourens , thanks for your check! I could fix it when I restarted the CI. Sorry for your inconvenience.
We will check it at Sunday. Thanks! :)

[sota1235]

LGTM

[sota1235]

@kazup01 Can you confirm how this PR works? If it is fine, please merge it.

[kazup01]

Merged.