Add Inverse Cumulative Probability as an option

[damonhook]

Often, it can be more relevant to know to probability of causing at least W wounds, rather than knowing the probability of causing no more than W wounds. I'd prefer to have P(X>=W) shown rather than P(X<=W).

[Spoofardio]

I added a PR for this: #42 (I think this is what you wanted)

[damonhook]

This has been released with version v0.5.0
Thanks @Spoofardio