Consolidate all info about specifying deps into one page.

Consolidate all info about specifying deps into one page.

I think information about specifying dependencies deserves to have its
own page since this info is commonly needed and there are a LOT of
different ways to specify dependencies.

Previously this information was spread across multiple pages, now
there's one place to go if you're looking for any of these ways, rather
than checking the multiple pages this info was spread across before.