Add /prelockdown command

Allows current tournaments to finish before progressing to a proper lockdown
So, we have this super important concept in programming, called "state". "State" refers to the different states that the program can be in. For instance, it can be in the state where `lockdown === true`, or it can be in the state where `lockdown === false`. So as you can see, the more non-local variables a program has, the more state it has.

The number of bugs a program has is pretty much exactly correlated with how much state it has. That's only one of many reasons why you want to decrease the amount of state a program has as much as possible.

Another reason is the possibility of _inconsistent_ state.

For instance, we have three states: normal, pre-lockdown, lockdown. But we have four possible states for `[lockdown, prelockdown]`. They could be `[false, false]`, `[false, true]`, `[true, false]`, or `[true, true]`. The number of states don't match up.

But what if instead `lockdown` were one of `true`, `false`, or `'pre'`? Then it would be obvious which state were which.