readme for firstrune program in the exam

subjects/firstruneprog.en.md

@@ -0,0 +1,19 @@
+## firstruneprog
+
+### Instructions
+
+Write a program that receives a `string` and returns the first `rune` of that `string`.
+
+### Expected output :
+
+```console
+student@ubuntu:~/piscine-go/firstruneprog$ go build
+student@ubuntu:~/piscine-go/firstruneprog$ ./firstruneprog "this is not happening"
+t
+student@ubuntu:~/piscine-go/firstruneprog$ ./firstruneprog "hello"
+h
+student@ubuntu:~/piscine-go/firstruneprog$ ./firstruneprog "this" "is" "not" "happening"
+student@ubuntu:~/piscine-go/firstruneprog$
+student@ubuntu:~/piscine-go/firstruneprog$ ./firstruneprog
+student@ubuntu:~/piscine-go/firstruneprog$
+```