Minor missing text in user guide's multivariate priors section

[bgall]

Summary:

Missing text in multivariate priors section of user guide.

Description:

Typo/omitted text in the multivariate priors section of the users guide. Comes at the end of this:

"Therefore, multiplying z by the Cholesky factor of the covariance matrix and adding the mean (u * gamma)' produces a beta distributed as in the original model, where the variance is"

Not sure what was intended to go there.

[bob-carpenter]

Thanks, @bgall. Feel free to submit a PR where you just chop everything out after the comma---you can just edit the markdown directly in the web app and convert to a PR.