Feature Request: Vault Timeout

[drew1horn]

I'm paranoid enough to worry about leaving my loxodo vault open on my desktop too long.

But I'm not paranoid enough to remember to close it every time I should.

I'd really like an option for set timer for n seconds.

After the vault has been open for the n seconds, a window pops up
with a button to click to reset the timer to get another n seconds,
If I don't click the button, the vault will automatically closes after n seconds.