start working on crack solution

Author: Mykolas Krupauskas

chapter2/crack.c

@@ -0,0 +1,12 @@
+#include <stdio.h>
+#include <cs50.h>
+
+int main(int argc, char **argv)
+{
+    // There must be two arguments
+    if (argc != 2)
+    {
+        printf("No key provided");
+        return 1;
+    }
+}