Update downloads to refer to fluo-parent and build-resources

I don't think these deserve a prominent display on the downloads page, because they're primarily used via Maven, but it'd be good to have a small, out-of-the-way section for these downloads.

Start at the website's downloads page and review how the existing downloads are organized. Add a small, less prominent section referring to fluo-parent and build-resources, while keeping them separate from the prominent downloads; done means both resources are clearly linked on that page.

Written by the indexing model from the issue text.