Add the ability to remove phrases as well as add

[lewisnyman]

Add the ability to remove phrases as well as add

[okize]

@lewisnyman That's a good idea! PRs are very welcome; I can probably get to it next week otherwise.

Also, I think "ping me" should probably be removed, that one triggers constantly for us.

[scit106]

I actually just added this, see #22

[okize]

@lewisnyman does #22 satisfy this issue for you?

[lewisnyman]

That's great, thank you! Looks like we need to update the readme