Unclear documentation on closure_repositories

In the docs you have:

> When you call closure_repositories() in your WORKSPACE file, it causes a few dozen external dependencies to be added to your project, e.g. Guava, Guice, JSR305, etc. You might need to customize this behavior.

What do you mean by "call closure_respositories()"? Are these invoked automatically the first time you invoke `bazel build`? Also, where exactly does it install the dependencies? Globally on the system or in the current workspace?

Start by locating the documentation passage about calling closure_repositories() in WORKSPACE files and compare it with the behavior of bazel build. Determine whether the dependencies are added automatically and where they are installed, then update the passage so invocation and dependency location are explicit.

Written by the indexing model from the issue text.