Add FreeRTOS to container image and demo project

freertos_test_project/main.cpp

@@ -0,0 +1,45 @@
+#include "FreeRTOS.h"
+#include "task.h"
+#include <stdio.h>
+#include "pico/stdlib.h"
+#include "hardware/gpio.h"
+
+#ifdef __cplusplus
+extern "C" {
+void vApplicationStackOverflowHook( TaskHandle_t pxTask, char *pcTaskName );
+void vApplicationTickHook( void );
+void vApplicationMallocFailedHook( void );
+}
+#endif
+
+void vApplicationStackOverflowHook( TaskHandle_t pxTask, char *pcTaskName ) {}
+void vApplicationTickHook( void ) {}
+void vApplicationMallocFailedHook( void ) {}
+
+void vBlink(void* unused_arg) {
+
+   for (;;) {
+
+      gpio_put(PICO_DEFAULT_LED_PIN, 1);
+
+      vTaskDelay(250);
+
+      gpio_put(PICO_DEFAULT_LED_PIN, 0);
+
+      vTaskDelay(250);
+
+   }
+
+}
+
+int main() {
+
+   gpio_init(PICO_DEFAULT_LED_PIN);
+
+   gpio_set_dir(PICO_DEFAULT_LED_PIN, GPIO_OUT);
+
+   xTaskCreate(vBlink, "Blink", 128, NULL, 1, NULL);
+
+   vTaskStartScheduler();
+
+}