OpenApi Guide Add-Extension Doesn't Work

[raffamendes]

When running the command from the guide

./mvnw quarkus:add-extension -Dextensions="openapi"

I got the following error:

I'll submit a pull request with the correct command.

./mvnw quarkus:add-extension -Dextensions="quarkus-smallrye-openapi"

[emmanuelbernard]

Applied on website and quarkus master.