Explicitly adopt an open source license

[jpgoldberg]

I have received a request to put this under an MIT or Creative Commons license. I am personally happy with either. Copyright would remain with 1Password, Inc

In its day this was something that we actively pointed the public to. As a reminder, this is where challenge details and results were published for the contest described in https://blog.1password.com/cracking-challenge-update/
So it was implicitly open source, but I failed to create a proper license when I created it.

Note that this does contain an outdated version of the wordlist used in the 1Password generator, but that word list is easy to extract from the apps. And we have told people how to see that list in a number of public discussions.