examples: add an even smaller gg usage example, demonstrating how to always show the builtin fps counter, and how to avoid importing gx

examples/gg/minimal.v

@@ -0,0 +1,19 @@
+import gg
+
+fn main() {
+	mut ctx := gg.new_context(
+		window_title: 'Hello'
+		bg_color: gg.Color{240, 240, 128, 255}
+		width: 320
+		height: 240
+		frame_fn: on_frame
+	)
+	ctx.run()
+}
+
+fn on_frame(ctx &gg.Context) {
+	ctx.begin()
+	ctx.draw_text(40, 100, 'GG frame: ${ctx.frame:06}', size: 30, color: gg.Color{50, 50, 255, 255})
+	ctx.show_fps()
+	ctx.end()
+}