Add live check and version update check

Casks/o/overlayed.rb

@@ -8,6 +8,13 @@ cask "overlayed" do
   desc "Modern, open-source, and free voice chat overlay for Discord"
   homepage "https://overlayed.dev/"
 
+  livecheck do
+    url :url
+    strategy :github_latest
+  end
+
+  depends_on macos: ">= :high_sierra"
+
   app "Overlayed.app"
 
   zap trash: "~/Library/Application Support/com.hacksore.overlayed"