Move the EventFlags example to an external repo

Author: fkjagodzinski

docs/api/rtos/EventFlags.md

@@ -10,33 +10,4 @@ The EventFlags class provides a mechanism for setting and waiting for specific c
 
 ### EventFlags example
 
-Below is an example of EventFlags usage, where one thread is generating events every 1s, and the second thread is waiting for the events and executing some action.
-
-<span class="images">![](https://s3-us-west-2.amazonaws.com/mbed-os-docs-images//eventflags_usage.png)</span>
-
-```
-#include "mbed.h"
-
-EventFlags event;
-
-void worker_f()
-{
-    while (true) {
-        event.wait_all(0x1);
-
-        printf("Got signal!\r\n");
-    }
-}
-
-int main()
-{
-    Thread worker;
-
-    worker.start(callback(worker_f));
-
-    while (true) {
-        wait(1);
-        event.set(0x1);
-    }
-}
-```
+[![View Example](https://www.mbed.com/embed/?url=https://github.com/ARMmbed/mbed-os-examples-docs_only)](https://github.com/ARMmbed/mbed-os-examples-docs_only/blob/master/EventFlags/main.cpp)