Cleanup (#43)

- Updated README.md, screenshot layout
- Cleanup of incorrect `TT_UNUSED` usage

app-esp/src/hello_world/hello_world.c

@@ -2,7 +2,7 @@
 #include "lvgl.h"
 #include "ui/toolbar.h"
 
-static void app_show(TT_UNUSED App app, lv_obj_t* parent) {
+static void app_show(App app, lv_obj_t* parent) {
     lv_obj_t* toolbar = tt_toolbar_create_for_app(parent, app);
     lv_obj_align(toolbar, LV_ALIGN_TOP_MID, 0, 0);
 

app-esp/src/main.c

@@ -10,7 +10,7 @@ extern const ServiceManifest wifi_service;
 extern const AppManifest wifi_connect_app;
 extern const AppManifest wifi_manage_app;
 
-TT_UNUSED void app_main(void) {
+void app_main(void) {
     static const Config config = {
         /**
          * Auto-select a board based on the ./sdkconfig.board.* file