BCR package

I noticed there is a BCR package with rules_jvm. Is it an official one? If yes, could you please refer to it in the documentation here?

Start by checking the BCR package mentioned in the issue and the repository's existing documentation locations. Confirm whether the package is official, then update the relevant documentation reference if it is; done means the documentation clearly points readers to the package.

Written by the indexing model from the issue text.