Add sample code for day 4 part 2

Author: pierredup

src/day4/test.php

@@ -9,5 +9,11 @@
     ],
 
     // part 2
-    []
-];
+    [
+        'abcde fghij' => 1,
+        'abcde xyz ecdab' => 0,
+        'a ab abc abd abf abj' => 1,
+        'iiii oiii ooii oooi oooo' => 1,
+        'oiii ioii iioi iiio' => 0,
+    ]
+];