[Docs] One typo in getting started.

[lrnv]

for random ve tors and random variables -> vectors in

Copulas.jl/docs/src/getting_started.md

Line 102 in 6d5f5c5

`Distributions.jl` proposes the `fit` function in their API for random ve tors and random variables. We used it to implement fitting of multivariate models (copulas, of course, but also compound distributions). It can be used as follows:

[lrnv]

Closed in favor of #143