command: Name the Terraform Registry specifically in error message
command: Name the Terraform Registry specifically in error message

When we originally wrote this message we struggled a bit for how to refer
to the releases server without writing an awkwardly-ungrammatical
sentence, and so "the official repository" became a placeholder name for
it.

Now that we'll be looking in Terraform Registry this gives us a nice
proper noun to use. This message will need to evolve more as our
integration with the registry gets more sophisticated, but for now this
works.

youhong316/terraform,nlamirault/terraform,VladRassokhin/terraform,pdecat/terraform,heimweh/terraform,tommynsong/terraform,luis-silva/terraform,mattray/terraform,heimweh/terraform,VladRassokhin/terraform,brandontosch/terraform,apparentlymart/terraform,mattray/terraform,drebes/terraform,luis-silva/terraform,tommynsong/terraform,apparentlymart/terraform,heimweh/terraform,hashicorp/terraform,youhong316/terraform,pryorda/terraform,nlamirault/terraform,tommynsong/terraform,iljaskevic/terraform,ewbankkit/terraform,pdecat/terraform,luis-silva/terraform,drebes/terraform,pryorda/terraform,iljaskevic/terraform,rnaveiras/terraform,pdecat/terraform,hashicorp/terraform,drebes/terraform,nlamirault/terraform,mattray/terraform,iljaskevic/terraform,apparentlymart/terraform,brandontosch/terraform,brandontosch/terraform,youhong316/terraform,mattray/terraform,youhong316/terraform,pdecat/terraform,drebes/terraform,rnaveiras/terraform,brandontosch/terraform,pradeepbhadani/terraform,gechr/terraform,gechr/terraform,pryorda/terraform,rnaveiras/terraform,luis-silva/terraform,pradeepbhadani/terraform,brandontosch/terraform,ewbankkit/terraform,gechr/terraform,ewbankkit/terraform,ewbankkit/terraform,iljaskevic/terraform,heimweh/terraform,pradeepbhadani/terraform,apparentlymart/terraform,VladRassokhin/terraform,VladRassokhin/terraform,hashicorp/terraform,apparentlymart/terraform,heimweh/terraform