Settings menu

[Hyperseeker]

Full-screen menu for adjustable settings. Required by #5. May be expanded to other options if necessary, including via tabs.

Should be perfectly navigable with keyboard alone, in line with the spirit of the game. Mouse navigation must be included as well.

Invoking the menu could be done with pressing [Ctrl] once or clicking on the settings icon. Entering settings menu should pause the round (if ongoing) and obscure current cells (to prevent cheating). Changes to difficulty should reset the ongoing round: generate a new password and set expired time to 0. Round pause should be indicated.

Tabs, if any, could be moved between using [Shift] for moving "forward" (to the right?) and [Alt] for moving "back".

Settings menu should be possible from the starting screen also, via the same methods.