Update readme for ForgeGradle
Update readme for ForgeGradle

Let me know if there's anything else to add or change.
dmf444/MinecraftForge,karlthepagan/MinecraftForge,CrafterKina/MinecraftForge,jdpadrnos/MinecraftForge,fcjailybo/MinecraftForge,Mathe172/MinecraftForge,ThiagoGarciaAlves/MinecraftForge,bonii-xx/MinecraftForge,simon816/MinecraftForge,luacs1998/MinecraftForge,Vorquel/MinecraftForge,blay09/MinecraftForge,mickkay/MinecraftForge,Zaggy1024/MinecraftForge,brubo1/MinecraftForge,RainWarrior/MinecraftForge,shadekiller666/MinecraftForge,Theerapak/MinecraftForge,Ghostlyr/MinecraftForge