Remove censusr package from list

[arilamstein]

In my branch where I add information on tutorials and documentation I am going to completely remove the entry for the censusr package. This is because on the package's github page they say:

We have decided to deprecate censusr and instead use (and contribute) to tidycensus. Censusr will remain on CRAN, but support will discontinue.

So I think that it is confusing for us to include it in the Guide.