Update epicardium_api_development.md

en/firmware/epicardium_api_development.md

@@ -39,17 +39,14 @@ The `*.c`-files need to be added to [`epicardium/modules/meson.build`](https://g
 An exemplary implementation to the declaration above could look like the following:
 ```c
 #include <stdio.h>
+#include "epicardium.h"
 
 void epic_example_call(int example_param_a, uint8_t example_param_b)
 {
-	while (1) {
-		printf ("I'm just an example!\n");
-	}
+	printf("I'm just an example!\n");
 }
 ```
 
-The `example.h` would go into [`lib/card10`](https://git.card10.badge.events.ccc.de/card10/firmware/tree/master/lib/card10).
-
 
 ## Best Practices