add pkgdown websites to azureR packages

I know that the information is all already out there, but I'm very used to the convenience/navigation/convention of pkgdown.
Perhaps other people feel the same way?

I'm (wildly) guessing that the lack of support for R6 in roxygen2 ([added in 7.0](https://www.tidyverse.org/blog/2019/11/roxygen2-7-0-0/#r6-documentation)) was a hurdle for this in the past.

I'd be happy to add make some PRs to this effect, though it probably needs the pkg author to fine tune the pkgdown site, especially the reference index.