Hello World App for Cohort 4

Revision:
0:66a527592d26
diff -r 000000000000 -r 66a527592d26 main.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Mon Mar 21 15:02:43 2022 +0000
@@ -0,0 +1,12 @@
+#include "mbed.h"
+
+DigitalOut led(LED1);
+
+int main() {
+    while (1) {
+        led = !led;
+        printf("Blink! LED is now %d\n", led.read());
+
+        wait_ms(5000);
+    }
+}