Add documentation link to bazel module.

[feuerste]

No description provided.

[feuerste]

@EmmanuelP I think it may be helpful to Bazel users to shortly mention its availability in the Bazel Central Registry. If you don't like this, just discard my PR :)

[EmmanuelP]

Hi @feuerste ,

Thanks for your work on this, but I prefer not to mention bazel as an alternative build system. I will not use it, and don't want to handle possible bazel related issues. Bazel users are likely to find aravis by themselves in the central registry.