[Feature Request] rep and dnorm functions

[fkukuck]

Great package. Would love to see the dnorm function added, and the rep function :+1:

[wrathematics]

Sorry for the delay. I've been swamped with work.

I've added rep() here. It will take more time to add the d/q functions, but -unif and -norm shouldn't be too bad. I'll try to do that soon.