Add link to War Plugin
Add link to War Plugin

Every time I read this I want that link to be there :)

MGronber/gradle-appengine-plugin,loosebazooka/gradle-appengine-plugin,judeebene/gradle-appengine-plugin,GoogleCloudPlatform/gradle-appengine-plugin,ArseniKavalchuk/gradle-appengine-plugin,mpoehler/gradle-appengine-plugin