various improvements

stopped using private header folder (for ease of development - for now)
implemented basic gui service (WIP)
added sdkconfig.defaults to the repo
updated docs

components/nanobake/src/nb_lvgl.h

@@ -0,0 +1,17 @@
+#pragma once
+
+#include <lvgl.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct nb_lvgl nb_lvgl_t;
+struct nb_lvgl {
+    lv_disp_t* _Nonnull disp;
+    lv_indev_t* _Nullable touch_indev;
+};
+
+#ifdef __cplusplus
+}
+#endif