workspace can document targets only (without packages)

[danwos]

Currently the workspace can only document target (or rules, macros, ...) if the levels before (e.g. packages) get also documented.

This should not be needed, so that it is easy possible to e.g. get a list of all macros inside a workspace without any other information.

Technical realisation:

If e.g. only autobazel-workspace with option rules is given, packages and targets needs to be collected as well. But their output shall be set to :hide:, if they are not part of the autobazel-workspace-option list.