Add an obvious in-game tip about the hotkeys Esc and F1

[BelugaHaechi]

The hotkeys Esc and F1 in bemuse are very useful for instantly exiting/restarting a game, but their existence isn't obvious enough for players to quickly know about. Esc is now explained to players in the Tutorial when they rage quit, but F1 took me a long time to find out — it was somewhere in the User Guide, located on a separate website.

Thus I suggest adding obvious in-game tips about these hotkeys, preferably in the Options menu.