embed Version string in app

* print version on app startup

main.go

@@ -9,7 +9,12 @@
 
 const appGreeting = "welcome to go-xkcdreader"
 
+// Version provides app version string
+const Version = "0.0.0"
+
 func main() {
+	fmt.Println("Starting go-xkcdreader " + getVersion())
+
 	a := app.New()
 	w := a.NewWindow("go-xkcd_reader")
 
@@ -23,3 +28,7 @@ func main() {
 func makeGreeting() *widget.Label {
 	return widget.NewLabel(appGreeting)
 }
+
+func getVersion() string {
+	return "v" + Version
+}