Added hello world program

rpm_packaging_guide_tut/cello/Makefile

@@ -0,0 +1,5 @@
+cello:
+		gcc -g -o cello cello.c
+
+clean:
+		rm cello

rpm_packaging_guide_tut/cello/cello.c

@@ -0,0 +1,6 @@
+#include <stdio.h>
+
+int main(){
+    printf("Hello World from C\n");
+    return 0;
+}