Providence article updated

Nothing major in the Providence article update, I just wanted to add in the new Flak Guns and DBYs now that they're released with the Venator. One new build for the Providence focusing on Flak Guns salvo. This brings us up to a Lucid Voice Carrier Providence salvo build and a Flak Guns DBYs Dreadnought Providence salvo build. They're distinct enough that it'll really depend on your fleet as to which you think you'd prefer.