Changed default screen size to match TRMNL OG

config_example.json

@@ -1,6 +1,6 @@
 {
 	"width": 800,
-	"height": 600,
+	"height": 480,
 	"output": "trmnl.png",
 	"font": "font.ttf",
 	"widgets":

main.cpp

@@ -33,7 +33,7 @@ int main(int argc, char **argv)
 	bool ok;
 
 	int screen_width = 800;
-	int screen_height = 600;
+	int screen_height = 480;
 	string output_filename = "trmnl.png";
 	string cfg_filename = "config.json";
 	json cfg;